CWE-400
DiscouragedUncontrolled Resource Consumption
Abstraction: Class · Status: Draft
The product does not properly control the allocation and maintenance of a limited resource.
5914 vulnerabilities reference this CWE, most recent first.
GHSA-WQXW-8H5G-HQ56
Vulnerability from github – Published: 2023-02-02 01:33 – Updated: 2023-02-15 17:35Impact
Unsanitized input flows into Strategy match operation (EXIST), where it is used to build a regular expression. This may result in a Regular expression Denial of Service attack (reDOS).
Patches
Patched in 3.1.4
Workarounds
Avoid using Strategy settings that use REGEX in conjunction with EXIST and NOT_EXIST operations.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "switcher-client"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-23925"
],
"database_specific": {
"cwe_ids": [
"CWE-1333",
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2023-02-02T01:33:06Z",
"nvd_published_at": "2023-02-03T20:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\nUnsanitized input flows into Strategy match operation (EXIST), where it is used to build a regular expression. This may result in a Regular expression Denial of Service attack (reDOS).\n\n### Patches\nPatched in 3.1.4\n\n### Workarounds\nAvoid using Strategy settings that use REGEX in conjunction with EXIST and NOT_EXIST operations.",
"id": "GHSA-wqxw-8h5g-hq56",
"modified": "2023-02-15T17:35:36Z",
"published": "2023-02-02T01:33:06Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/switcherapi/switcher-client-master/security/advisories/GHSA-wqxw-8h5g-hq56"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-23925"
},
{
"type": "WEB",
"url": "https://github.com/switcherapi/switcher-client-master/commit/374752563d6ce9353ee592b40c809c8136f24930"
},
{
"type": "PACKAGE",
"url": "https://github.com/switcherapi/switcher-client-master"
},
{
"type": "WEB",
"url": "https://github.com/switcherapi/switcher-client-master/releases/tag/v3.1.4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Switcher Client contains Regular Expression Denial of Service (ReDoS)"
}
GHSA-WR66-VRWM-5G5X
Vulnerability from github – Published: 2022-01-28 23:09 – Updated: 2022-02-07 21:17Impact
Vulnerable code could allow a bad actor to trigger a denial of service attack for anyone running a Next.js app at version >= 12.0.0, and using i18n functionality.
- Affected: All of the following must be true to be affected by this CVE
- Next.js versions above v12.0.0
- Using next start or a custom server
- Using the built-in i18n support
- Not affected:
- Deployments on Vercel (vercel.com) are not affected along with similar environments where invalid requests are filtered before reaching Next.js.
Patches
A patch has been released, next@12.0.9, that mitigates this issue. We recommend all affected users upgrade as soon as possible.
Workarounds
We recommend upgrading whether you can reproduce or not although you can ensure /${locale}/_next/ is blocked from reaching the Next.js instance until you upgrade.
For more information
If you have any questions or comments about this advisory: * Open an issue in next * Email us at security@vercel.com
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "next"
},
"ranges": [
{
"events": [
{
"introduced": "12.0.0"
},
{
"fixed": "12.0.9"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-21721"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2022-01-28T18:52:54Z",
"nvd_published_at": "2022-01-28T22:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nVulnerable code could allow a bad actor to trigger a denial of service attack for anyone running a Next.js app at version \u003e= 12.0.0, and using i18n functionality.\n\n- **Affected:** All of the following must be true to be affected by this CVE\n - Next.js versions above v12.0.0\n - Using next start or a custom server\n - Using the built-in i18n support\n- **Not affected:**\n - Deployments on Vercel (vercel.com) are not affected along with similar environments where invalid requests are filtered before reaching Next.js.\n\n### Patches\n\nA patch has been released, `next@12.0.9`, that mitigates this issue. We recommend all affected users upgrade as soon as possible.\n\n### Workarounds\n\nWe recommend upgrading whether you can reproduce or not although you can ensure `/${locale}/_next/` is blocked from reaching the Next.js instance until you upgrade.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* Open an issue in [next](https://github.com/vercel/next.js)\n* Email us at [security@vercel.com](mailto:security@vercel.com)\n",
"id": "GHSA-wr66-vrwm-5g5x",
"modified": "2022-02-07T21:17:29Z",
"published": "2022-01-28T23:09:22Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/vercel/next.js/security/advisories/GHSA-wr66-vrwm-5g5x"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-21721"
},
{
"type": "WEB",
"url": "https://github.com/vercel/next.js/pull/33503"
},
{
"type": "PACKAGE",
"url": "https://github.com/vercel/next.js"
},
{
"type": "WEB",
"url": "https://github.com/vercel/next.js/releases/tag/v12.0.9"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Denial of Service Vulnerability in next.js"
}
GHSA-WR6M-JG37-68XH
Vulnerability from github – Published: 2026-03-02 21:49 – Updated: 2026-03-23 21:52Summary
Unauthenticated requests to a reachable Zalo webhook endpoint could trigger unbounded in-memory key growth by varying query strings on the same valid webhook route.
Impact
An attacker could cause memory pressure and potential process instability or OOM, degrading availability.
Fix
Webhook security tracking now normalizes keys to matched webhook path semantics (query excluded) and bounds/prunes tracking state to prevent unbounded growth.
Affected and Patched Versions
- Affected:
<= 2026.2.26 - Patched:
2026.3.1
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "openclaw"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.3.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-32066"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-02T21:49:51Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\nUnauthenticated requests to a reachable Zalo webhook endpoint could trigger unbounded in-memory key growth by varying query strings on the same valid webhook route.\n\n### Impact\nAn attacker could cause memory pressure and potential process instability or OOM, degrading availability.\n\n### Fix\nWebhook security tracking now normalizes keys to matched webhook path semantics (query excluded) and bounds/prunes tracking state to prevent unbounded growth.\n\n### Affected and Patched Versions\n- Affected: `\u003c= 2026.2.26`\n- Patched: `2026.3.1`",
"id": "GHSA-wr6m-jg37-68xh",
"modified": "2026-03-23T21:52:21Z",
"published": "2026-03-02T21:49:51Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-wr6m-jg37-68xh"
},
{
"type": "PACKAGE",
"url": "https://github.com/openclaw/openclaw"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "OpenClaw has unbounded memory growth in Zalo webhook via query-string key churn (unauthenticated DoS)"
}
GHSA-WR6Q-54PC-3F46
Vulnerability from github – Published: 2024-05-17 12:30 – Updated: 2024-05-17 12:30Denial of Service (DoS) vulnerability for Cerberus Enterprise 8.0.10.3 web administration. The vulnerability exists when the web server, default port 10001, attempts to process a large number of incomplete HTTP requests.
{
"affected": [],
"aliases": [
"CVE-2024-5052"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-17T10:15:14Z",
"severity": "HIGH"
},
"details": "Denial of Service (DoS) vulnerability for Cerberus Enterprise 8.0.10.3 web administration. The vulnerability exists when the web server, default port 10001, attempts to process a large number of incomplete HTTP requests.",
"id": "GHSA-wr6q-54pc-3f46",
"modified": "2024-05-17T12:30:59Z",
"published": "2024-05-17T12:30:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-5052"
},
{
"type": "WEB",
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/resource-consumption-vulnerability-cerberus-ftp-enterprise"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WRC7-97QH-J6MH
Vulnerability from github – Published: 2024-06-09 15:31 – Updated: 2024-07-03 18:44GNOME VTE before 0.76.3 allows an attacker to cause a denial of service (memory consumption) via a window resize escape sequence, a related issue to CVE-2000-0476.
{
"affected": [],
"aliases": [
"CVE-2024-37535"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-09T15:16:00Z",
"severity": "MODERATE"
},
"details": "GNOME VTE before 0.76.3 allows an attacker to cause a denial of service (memory consumption) via a window resize escape sequence, a related issue to CVE-2000-0476.",
"id": "GHSA-wrc7-97qh-j6mh",
"modified": "2024-07-03T18:44:20Z",
"published": "2024-06-09T15:31:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-37535"
},
{
"type": "WEB",
"url": "https://gitlab.gnome.org/GNOME/vte/-/issues/2786"
},
{
"type": "WEB",
"url": "https://gitlab.gnome.org/GNOME/vte/-/tags/0.76.3"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2024/06/09/1"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2024/06/09/2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WRCR-X4QJ-J543
Vulnerability from github – Published: 2022-07-11 21:05 – Updated: 2022-07-19 21:05Impact
The Cloud Stream server and the Edge Stream server reads the entire message into memory without imposing a limit on the size of this message. An attacker can exploit this by sending a large message to exhaust memory and cause a DoS. The Cloud Stream server and the Edge Stream server are under DoS attack in this case. The consequence of the exhaustion is that the CloudCore and EdgeCore will be in a denial of service. Only an authenticated user can cause this issue. It will be affected only when users enable cloudStream module in the config file cloudcore.yaml and enable edgeStream module in the config file edgecore.yaml as below. cloudcore.yaml:
modules:
...
cloudStream:
enable: true
edgecore.yaml:
modules:
...
edgeStream:
enable: true
Patches
This bug has been fixed in Kubeedge 1.11.1, 1.10.2, 1.9.4. Users should update to these versions to resolve the issue.
Workarounds
Disable cloudStream module in the config file cloudcore.yaml and disable edgeStream module in the config file edgecore.yaml, restart process cloudcore and edgecore after modification.
References
NA
Credits
Thanks David Korczynski and Adam Korczynski of ADA Logics for responsibly disclosing this issue in accordance with the kubeedge security policy during a security audit sponsored by CNCF and facilitated by OSTIF.
For more information
If you have any questions or comments about this advisory: * Open an issue in KubeEdge repo * To make a vulnerability report, email your vulnerability to the private cncf-kubeedge-security@lists.cncf.io list with the security details and the details expected for KubeEdge bug reports.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/kubeedge/kubeedge"
},
"ranges": [
{
"events": [
{
"introduced": "1.11.0"
},
{
"fixed": "1.11.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Go",
"name": "github.com/kubeedge/kubeedge"
},
"ranges": [
{
"events": [
{
"introduced": "1.10.0"
},
{
"fixed": "1.10.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Go",
"name": "github.com/kubeedge/kubeedge"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.9.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-31079"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2022-07-11T21:05:32Z",
"nvd_published_at": "2022-07-11T21:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\nThe Cloud Stream server and the Edge Stream server reads the entire message into memory without imposing a limit on the size of this message. An attacker can exploit this by sending a large message to exhaust memory and cause a DoS. The Cloud Stream server and the Edge Stream server are under DoS attack in this case. The consequence of the exhaustion is that the CloudCore and EdgeCore will be in a denial of service.\nOnly an authenticated user can cause this issue. It will be affected only when users enable cloudStream module in the config file cloudcore.yaml and enable edgeStream module in the config file edgecore.yaml as below.\ncloudcore.yaml:\n```\nmodules:\n ...\n cloudStream:\n enable: true\n```\nedgecore.yaml:\n```\nmodules:\n ...\n edgeStream:\n enable: true\n```\n\n### Patches\nThis bug has been fixed in Kubeedge 1.11.1, 1.10.2, 1.9.4. Users should update to these versions to resolve the issue.\n\n### Workarounds\nDisable cloudStream module in the config file cloudcore.yaml and disable edgeStream module in the config file edgecore.yaml, restart process cloudcore and edgecore after modification.\n\n### References\nNA\n\n### Credits\nThanks David Korczynski and Adam Korczynski of ADA Logics for responsibly disclosing this issue in accordance with the [kubeedge security policy](https://github.com/kubeedge/kubeedge/security/policy) during a security audit sponsored by CNCF and facilitated by OSTIF.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [KubeEdge repo](https://github.com/kubeedge/kubeedge/issues/new/choose)\n* To make a vulnerability report, email your vulnerability to the private [cncf-kubeedge-security@lists.cncf.io](mailto:cncf-kubeedge-security@lists.cncf.io) list with the security details and the details expected for [KubeEdge bug reports](https://github.com/kubeedge/kubeedge/blob/master/.github/ISSUE_TEMPLATE/bug-report.md).\n",
"id": "GHSA-wrcr-x4qj-j543",
"modified": "2022-07-19T21:05:39Z",
"published": "2022-07-11T21:05:32Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/kubeedge/kubeedge/security/advisories/GHSA-wrcr-x4qj-j543"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-31079"
},
{
"type": "PACKAGE",
"url": "https://github.com/kubeedge/kubeedge"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "KubeEdge Cloud Stream and Edge Stream DoS from large stream message"
}
GHSA-WRP8-556F-JX6R
Vulnerability from github – Published: 2022-04-30 18:10 – Updated: 2025-08-27 21:31Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.
{
"affected": [],
"aliases": [
"CVE-1999-0159"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "1998-08-12T04:00:00Z",
"severity": "MODERATE"
},
"details": "Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.",
"id": "GHSA-wrp8-556f-jx6r",
"modified": "2025-08-27T21:31:34Z",
"published": "2022-04-30T18:10:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-1999-0159"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0159"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-WRVR-8MPX-R7PP
Vulnerability from github – Published: 2018-07-20 16:20 – Updated: 2023-09-12 18:28Affected versions of mime are vulnerable to regular expression denial of service when a mime lookup is performed on untrusted user input.
Recommendation
Update to version 2.0.3 or later.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "mime"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.0"
},
{
"fixed": "2.0.3"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "mime"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.4.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2017-16138"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2020-06-16T22:01:10Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "Affected versions of `mime` are vulnerable to regular expression denial of service when a mime lookup is performed on untrusted user input.\n\n\n## Recommendation\n\nUpdate to version 2.0.3 or later.",
"id": "GHSA-wrvr-8mpx-r7pp",
"modified": "2023-09-12T18:28:52Z",
"published": "2018-07-20T16:20:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-16138"
},
{
"type": "WEB",
"url": "https://github.com/broofa/node-mime/issues/167"
},
{
"type": "WEB",
"url": "https://github.com/broofa/mime/commit/1df903fdeb9ae7eaa048795b8d580ce2c98f40b0"
},
{
"type": "WEB",
"url": "https://github.com/broofa/mime/commit/855d0c4b8b22e4a80b9401a81f2872058eae274d"
},
{
"type": "PACKAGE",
"url": "https://github.com/broofa/mime"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "mime Regular Expression Denial of Service when MIME lookup performed on untrusted user input"
}
GHSA-WV35-897X-F828
Vulnerability from github – Published: 2022-05-24 17:12 – Updated: 2022-05-24 17:12The SSH daemon on MikroTik routers through v6.44.3 could allow remote attackers to generate CPU activity, trigger refusal of new authorized connections, and cause a reboot via connect and write system calls, because of uncontrolled resource management.
{
"affected": [],
"aliases": [
"CVE-2020-10364"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-03-23T16:15:00Z",
"severity": "MODERATE"
},
"details": "The SSH daemon on MikroTik routers through v6.44.3 could allow remote attackers to generate CPU activity, trigger refusal of new authorized connections, and cause a reboot via connect and write system calls, because of uncontrolled resource management.",
"id": "GHSA-wv35-897x-f828",
"modified": "2022-05-24T17:12:13Z",
"published": "2022-05-24T17:12:13Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-10364"
},
{
"type": "WEB",
"url": "https://packetstormsecurity.com/files/156790/Microtik-SSH-Daemon-6.44.3-Denial-Of-Service.html"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/48228"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-WV94-5QCP-6M36
Vulnerability from github – Published: 2026-08-25 14:34 – Updated: 2026-08-25 14:34Summary
The PraisonAI MCP HTTP-stream server creates a new in-memory session on every initialize request and never removes it. The cleanup routine that would expire sessions (_cleanup_sessions) is defined but never called anywhere in the codebase, and the configured session TTL is never enforced. There is no cap on the number of sessions. Because initialize requires no authentication and the server keeps every session dictionary forever, an attacker who can reach the endpoint (directly when the server is bound to a routable address, or from a victim's browser via the separate Origin-validation bypass) can drive memory usage up without bound until the process is killed by the out-of-memory killer. The same unbounded-growth pattern also applies to the cancelled-requests set populated by notifications/cancelled.
Details
In transports/http_stream.py, each initialize creates and stores a session with no limit:
if body.get("method") == "initialize":
new_session_id = str(uuid.uuid4())
self._sessions[new_session_id] = {
"created_at": time.time(),
"last_activity": time.time(),
}
A cleanup method exists:
def _cleanup_sessions(self) -> None:
now = time.time()
expired = [sid for sid, data in self._sessions.items()
if now - data["last_activity"] > self.session_ttl]
for sid in expired:
del self._sessions[sid]
but grep across the package shows it has no call sites: it is never invoked on a timer, on request handling, or from any background task. self.session_ttl (default 3600) is stored and otherwise unused. There is no maximum-session check anywhere on the write path. As a result self._sessions grows monotonically for the lifetime of the process.
initialize is unauthenticated: in mcp_post the API-key check is skipped when no key is configured (the default), and initialize does not require a prior session. The Origin check is the only gate, and a request with no Origin header is allowed; additionally the Origin allowlist is bypassable (see the companion report on the startswith Origin-validation bypass), so the endpoint is reachable from a malicious web page as well as directly.
The server-side cancellation set in server.py has the same defect:
if method == "notifications/cancelled":
request_id = params.get("requestId")
if request_id:
self._cancelled_requests.add(str(request_id)) # never cleared
self._cancelled_requests is an unbounded set that is added to but never pruned.
PoC
scripts/poc_mcp_session_dos.sh. Start the server (default config, no API key):
praisonai mcp serve --transport http-stream --host 127.0.0.1 --port 8080
Send repeated initialize requests and watch the active session count grow:
for i in $(seq 1 200); do
curl -s -o /dev/null -X POST http://127.0.0.1:8080/mcp \
-H 'Content-Type: application/json' -H 'Origin: http://localhost' \
-d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"x","version":"1"}}}'
done
curl -s http://127.0.0.1:8080/health
Observed on 4.6.52 after 200 requests:
{"status":"healthy","server":"praisonai","version":"1.0.0","protocol_version":"2025-11-25","active_sessions":200}
The count rises by one per request and never decreases; there is no TTL expiry and no cap. Sustained requests grow the process resident set without bound. Each session also retains any SSE event history keyed by session id, amplifying the per-session footprint.
Impact
An unauthenticated client can exhaust the memory of the host running the MCP server, leading to denial of service (the process is terminated by the OOM killer, taking down the agent endpoint). When the server is bound to a routable interface (for example --host 0.0.0.0, common in containers), this is a direct remote unauthenticated DoS. With the default localhost bind, it is reachable from any web page the operator visits, because initialize is unauthenticated and the Origin gate is bypassable. The defect is a missing cleanup wiring plus the absence of any session cap, so it manifests even under benign long-running use.
Remediation
Enforce the session TTL and cap the number of concurrent sessions: call _cleanup_sessions periodically (a background asyncio task, or opportunistically on each request) and reject new sessions with a 429/503 once a configurable maximum is reached. Bound _cancelled_requests similarly (for example an LRU or a periodic prune keyed by age), since it is also never cleared. Require authentication by default on the HTTP-stream transport so that anonymous clients cannot create sessions at all.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "PraisonAI"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.6.58"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-55531"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-25T14:34:28Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\n\nThe PraisonAI MCP HTTP-stream server creates a new in-memory session on every initialize request and never removes it. The cleanup routine that would expire sessions (_cleanup_sessions) is defined but never called anywhere in the codebase, and the configured session TTL is never enforced. There is no cap on the number of sessions. Because initialize requires no authentication and the server keeps every session dictionary forever, an attacker who can reach the endpoint (directly when the server is bound to a routable address, or from a victim\u0027s browser via the separate Origin-validation bypass) can drive memory usage up without bound until the process is killed by the out-of-memory killer. The same unbounded-growth pattern also applies to the cancelled-requests set populated by notifications/cancelled.\n\n### Details\n\nIn transports/http_stream.py, each initialize creates and stores a session with no limit:\n\n```python\nif body.get(\"method\") == \"initialize\":\n new_session_id = str(uuid.uuid4())\n self._sessions[new_session_id] = {\n \"created_at\": time.time(),\n \"last_activity\": time.time(),\n }\n```\n\nA cleanup method exists:\n\n```python\ndef _cleanup_sessions(self) -\u003e None:\n now = time.time()\n expired = [sid for sid, data in self._sessions.items()\n if now - data[\"last_activity\"] \u003e self.session_ttl]\n for sid in expired:\n del self._sessions[sid]\n```\n\nbut grep across the package shows it has no call sites: it is never invoked on a timer, on request handling, or from any background task. self.session_ttl (default 3600) is stored and otherwise unused. There is no maximum-session check anywhere on the write path. As a result self._sessions grows monotonically for the lifetime of the process.\n\ninitialize is unauthenticated: in mcp_post the API-key check is skipped when no key is configured (the default), and initialize does not require a prior session. The Origin check is the only gate, and a request with no Origin header is allowed; additionally the Origin allowlist is bypassable (see the companion report on the startswith Origin-validation bypass), so the endpoint is reachable from a malicious web page as well as directly.\n\nThe server-side cancellation set in server.py has the same defect:\n\n```python\nif method == \"notifications/cancelled\":\n request_id = params.get(\"requestId\")\n if request_id:\n self._cancelled_requests.add(str(request_id)) # never cleared\n```\n\nself._cancelled_requests is an unbounded set that is added to but never pruned.\n\n### PoC\n\nscripts/poc_mcp_session_dos.sh. Start the server (default config, no API key):\n\n```\npraisonai mcp serve --transport http-stream --host 127.0.0.1 --port 8080\n```\n\nSend repeated initialize requests and watch the active session count grow:\n\n```bash\nfor i in $(seq 1 200); do\n curl -s -o /dev/null -X POST http://127.0.0.1:8080/mcp \\\n -H \u0027Content-Type: application/json\u0027 -H \u0027Origin: http://localhost\u0027 \\\n -d \u0027{\"jsonrpc\":\"2.0\",\"id\":1,\"method\":\"initialize\",\"params\":{\"protocolVersion\":\"2025-06-18\",\"capabilities\":{},\"clientInfo\":{\"name\":\"x\",\"version\":\"1\"}}}\u0027\ndone\ncurl -s http://127.0.0.1:8080/health\n```\n\nObserved on 4.6.52 after 200 requests:\n\n```\n{\"status\":\"healthy\",\"server\":\"praisonai\",\"version\":\"1.0.0\",\"protocol_version\":\"2025-11-25\",\"active_sessions\":200}\n```\n\nThe count rises by one per request and never decreases; there is no TTL expiry and no cap. Sustained requests grow the process resident set without bound. Each session also retains any SSE event history keyed by session id, amplifying the per-session footprint.\n\n### Impact\n\nAn unauthenticated client can exhaust the memory of the host running the MCP server, leading to denial of service (the process is terminated by the OOM killer, taking down the agent endpoint). When the server is bound to a routable interface (for example --host 0.0.0.0, common in containers), this is a direct remote unauthenticated DoS. With the default localhost bind, it is reachable from any web page the operator visits, because initialize is unauthenticated and the Origin gate is bypassable. The defect is a missing cleanup wiring plus the absence of any session cap, so it manifests even under benign long-running use.\n\n### Remediation\n\nEnforce the session TTL and cap the number of concurrent sessions: call _cleanup_sessions periodically (a background asyncio task, or opportunistically on each request) and reject new sessions with a 429/503 once a configurable maximum is reached. Bound _cancelled_requests similarly (for example an LRU or a periodic prune keyed by age), since it is also never cleared. Require authentication by default on the HTTP-stream transport so that anonymous clients cannot create sessions at all.",
"id": "GHSA-wv94-5qcp-6m36",
"modified": "2026-08-25T14:34:28Z",
"published": "2026-08-25T14:34:28Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-wv94-5qcp-6m36"
},
{
"type": "WEB",
"url": "https://github.com/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828fd0141612e1"
},
{
"type": "PACKAGE",
"url": "https://github.com/MervinPraison/PraisonAI"
},
{
"type": "WEB",
"url": "https://github.com/MervinPraison/PraisonAI/releases/tag/v4.6.58"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "PraisonAI MCP HTTP server has unauthenticated unbounded session accumulation (memory exhaustion; session TTL never enforced)"
}
Mitigation
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
Mitigation
- Mitigation of resource exhaustion attacks requires that the target system either:
- The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
- The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
- recognizes the attack and denies that user further access for a given amount of time, or
- uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Mitigation
Ensure that protocols have specific limits of scale placed on them.
Mitigation
Ensure that all failures in resource allocation place the system into a safe posture.
CAPEC-147: XML Ping of the Death
An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
CAPEC-227: Sustained Client Engagement
An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.
CAPEC-492: Regular Expression Exponential Blowup
An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.