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GCVE-1988-2026-0235

Vulnerability from gna-1988 – Published: 2026-09-08 08:13 – Updated: 2026-09-11 11:15
VLAI
Title
Dovecot Security Advisory OXDC-2026-0001
Summary
Dear subscribers, we're sharing our latest advisory with you and like to thank everyone who contributed in finding and solving those vulnerabilities. This advisory is also published at https://documentation.open-xchange.com/dovecot/security/advisories/html/2026/oxdc-adv-2026-0001.html --- Classification: TLP:GREEN Internal reference: DOV-7830 Type: CWE-1250 (Improper Preservation of Consistency Between Independent Representations of Shared State) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot CE core 2.4.1 Discovery date: 2025-07-24 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: Erik <erik () broadlux com> CVE: CVE-2025-30189 CVSS: 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) Details: v2.4 regression: auth cache broken with several passdb / userdb. When cache is enabled, some passdb/userdb drivers incorrectly cache all users with same cache key, causing wrong cached information to be used for these users. Risk: After cached login, all subsequent logins are for same user. No publicly available exploits are known. Solution: Install fixed version or disable caching either globally or for the impacted passdb/userdb drivers. --- Internal reference: DOV-8349 Type: CWE-20 (Improper Input Validation) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot Pro core 3.1.2, OX Dovecot CE core 2.4.3 Discovery date: 2025-11-04 Solution date: 2026-03-27 Disclosure date: 2026-03-27 CVE: CVE-2025-59028 CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) Details: Invalid base64 authentication can cause DoS for other logins. When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail. Risk: Invalid BASE64 data can be used to DoS a vulnerable server to break concurrent logins. No publicly available exploits are known. Solution: Install fixed version or disable concurrency in login processes (heavy perfomance penalty on large deployments). --- Internal reference: DOV-8508 Type: CWE-20 (Improper Input Validation) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.3 Discovery date: 2025-11-29 Solution date: 2026-03-27 Disclosure date: 2026-03-27 CVE: CVE-2025-59032 CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Details: v2.4/v3.1 regression: Pigeonhole: ManageSieve panic occurs with sieve-connect as a client. ManageSieve AUTHENTICATE command crashes when using literal as SASL initial response. Risk: This can be used to crash ManageSieve service repeatedly, making it unavailable for other users. No publicly available exploits are known. Solution: Control access to ManageSieve port, or disable the service if it's not needed. Alternatively upgrade to a fixed version. --- Internal reference: DOV-8584 Type: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 2.3.0 First fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.3, OX Dovecot Pro core 2.3.22.1 Discovery date: 2025-12-29 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: cavid@yeswehack CVE: CVE-2025-59031 CVSS: 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N) Details: decode2text.sh OOXML extraction may follow symlinks and read unintended files during indexing. Dovecot has provided a script to use for attachment to text conversion. This script unsafely handles zip-style attachments. Risk: Attacker can use specially crafted OOXML documents to cause unintended files on the system to be indexed and subsequently ending up in FTS indexes. No publicly available exploits are known. Solution: Do not use the provided script, instead, use something else like FTS tika. --- Internal reference: DOV-8591 Type: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 2.3.0 First fixed revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 Discovery date: 2026-01-07 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: strokep@yeswehack CVE: CVE-2026-0394 CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) Details: auth: Path traversal in passwd-file passdb using `%d` (domain) escapes base directory and opens `/etc/passwd`Pre-auth path traversal in passwd-file passdb using `%d` (domain) escapes base directory and opens `/etc/passwd`. When dovecot has been configured to use per-domain passwd files, and they are placed one path component above /etc, or slash has been added to allowed characters, path traversal can happen if the domain component is directory partial. Risk: This allows inadvertently reading /etc/passwd (or some other path which ends with passwd). If this file contains passwords, it can be used to authenticate wrongly, or if this is userdb, it can unexpectly make system users appear valid users. No publicly available exploits are known. Solution: Upgrade to fixed version, or use different authentication scheme that does not rely on paths. Alternatively you can also ensure that the per-domain passwd files are in some other location, such as /etc/dovecot/auth/%d. --- Internal reference: DOV-8775 Type: CWE-90 (Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4 Discovery date: 2026-02-20 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: cookiejack15@yeswehack CVE: CVE-2026-27860 CVSS: 3.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N) Details: v2.4/v3.1 regression: auth-ldap is not escaping usernames. If auth_username_chars is empty, it is possible to inject arbitrary LDAP filter to Dovecot's LDAP authentication. Risk: This leads to potentially bypassing restrictions and allows probing of LDAP structure. No publicly available exploits are known. Solution: Do not clear out auth_username_chars, or install fixed version. --- Internal reference: DOV-8781 Type: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4 Discovery date: 2026-02-23 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: whisperer@yeswehack CVE: CVE-2026-24031 CVSS: 7.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L) Details: v2.4/v3.1 regression: SQL injection allows bypassing authentication. Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. Risk: This vulnerability allows bypassing authentication for any user and user enumeration. No publicly available exploits are known. Solution: Do not clear auth_username_chars. If this is not possible, install latest fixed version. --- Internal reference: DOV-8787 Type: CWE-400 (Uncontrolled Resource Consumption) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 3.0.2, OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4 Discovery date: 2026-02-24 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: djvirus@yeswehack CVE: CVE-2026-27859 CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) Details: v3.0.2+ regression: Message headers MIME parameter parsing can cause excessive CPU usage. A mail message containing excessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU. Risk: A suitably formatted mail message causes mail delivery process to consume large amounts of CPU time. No publicly available exploits are known. Solution: Use MTA capabilities to limit RFC 2231 MIME parameters in mail messages, or upgrade to fixed version where the processing is limited. --- Internal reference: DOV-8816 Type: CWE-400 (Uncontrolled Resource Consumption) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 2.3.0 First fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4, OX Dovecot Pro core 2.3.22.1 Discovery date: 2026-02-27 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: whisperer@yeswehack CVE: CVE-2026-27857 CVSS: 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L) Details: imap-login: Excessive memory usage DoS. Sending "NOOP (((...)))" command with 4000 parenthesis open+close results in ~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for longer time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Risk: Attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. No publicly available exploits are known. Solution: Install fixed version, there is no other remediation. --- Internal reference: DOV-8818 Type: CWE-400 (Uncontrolled Resource Consumption) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 2.3.0, OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0 First fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4, OX Dovecot Pro core 2.3.22.1 Discovery date: 2026-02-28 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: ilyar@yeswehack CVE: CVE-2026-27858 CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Details: managesieve-login out-of-memory DoS. Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory. Risk: Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. No publicly available exploits are known. Solution: Protect access to managesieve protocol, or install fixed version. --- Internal reference: DOV-8830 Type: CWE-287 (Improper Authentication) Component: core Report confidence: Confirmed Solution status: Fixed by vendor Last affected revision: OX Dovecot Pro core 2.3.0 First fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4, OX Dovecot Pro core 2.3.22.1 Discovery date: 2026-03-04 Solution date: 2026-03-27 Disclosure date: 2026-03-27 Researcher credits: bksparajuli@yeswehack CVE: CVE-2026-27856 CVSS: 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) Details: doveadm: Credentials verified without timing safety. Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack. An attacker can use this to determine the configured credentials. Risk: Figuring out the credential will le
Severity
No CVSS data available.
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Dovecot Security Advisory Affected: unknown
guessed Create a notification for this product.
Credits
Aki Tuomi
Relationships
reference GCVE-1988-2026-0235 (this record)
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "Security Advisory",
          "vendor": "Dovecot",
          "versions": [
            {
              "status": "affected",
              "version": "unknown"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Aki Tuomi"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Dear subscribers,\n\nwe\u0027re sharing our latest advisory with you and like to thank everyone who contributed in finding and solving those \nvulnerabilities. This advisory is also published at \nhttps://documentation.open-xchange.com/dovecot/security/advisories/html/2026/oxdc-adv-2026-0001.html\n\n\n---\n\n\nClassification: TLP:GREEN\n\nInternal reference: DOV-7830\nType: CWE-1250 (Improper Preservation of Consistency Between Independent Representations of Shared State)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot CE core 2.4.1\nDiscovery date: 2025-07-24\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: Erik  \u003cerik () broadlux com\u003e\nCVE: CVE-2025-30189\nCVSS: 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)\n\nDetails:\nv2.4 regression: auth cache broken with several passdb / userdb. When cache is enabled, some passdb/userdb drivers \nincorrectly cache all users with same cache key, causing wrong cached information to be used for these users.\n\nRisk:\nAfter cached login, all subsequent logins are for same user. No publicly available exploits are known.\n\nSolution:\nInstall fixed version or disable caching either globally or for the impacted passdb/userdb drivers.\n\n\n\n---\n\n\n\nInternal reference: DOV-8349\nType: CWE-20 (Improper Input Validation)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot Pro core 3.1.2, OX Dovecot CE core 2.4.3\nDiscovery date: 2025-11-04\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nCVE: CVE-2025-59028\nCVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)\n\nDetails:\nInvalid base64 authentication can cause DoS for other logins. When sending invalid base64 SASL data, login process is \ndisconnected from the auth server, causing all active authentication sessions to fail.\n\nRisk:\nInvalid BASE64 data can be used to DoS a vulnerable server to break concurrent logins. No publicly available exploits \nare known.\n\nSolution:\nInstall fixed version or disable concurrency in login processes (heavy perfomance penalty on large deployments).\n\n\n\n---\n\n\n\nInternal reference: DOV-8508\nType: CWE-20 (Improper Input Validation)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.3\nDiscovery date: 2025-11-29\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nCVE: CVE-2025-59032\nCVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)\n\nDetails:\nv2.4/v3.1 regression: Pigeonhole: ManageSieve panic occurs with sieve-connect as a client. ManageSieve AUTHENTICATE \ncommand crashes when using literal as SASL initial response.\n\nRisk:\nThis can be used to crash ManageSieve service repeatedly, making it unavailable for other users. No publicly available \nexploits are known.\n\nSolution:\nControl access to ManageSieve port, or disable the service if it\u0027s not needed. Alternatively upgrade to a fixed version.\n\n\n\n---\n\n\n\nInternal reference: DOV-8584\nType: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 2.3.0\nFirst fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.3, OX Dovecot Pro core 2.3.22.1\nDiscovery date: 2025-12-29\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: cavid@yeswehack\nCVE: CVE-2025-59031\nCVSS: 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)\n\nDetails:\ndecode2text.sh OOXML extraction may follow symlinks and read unintended files during indexing. Dovecot has provided a \nscript to use for attachment to text conversion. This script unsafely handles zip-style attachments.\n\nRisk:\nAttacker can use specially crafted OOXML documents to cause unintended files on the system to be indexed and \nsubsequently ending up in FTS indexes. No publicly available exploits are known.\n\nSolution:\nDo not use the provided script, instead, use something else like FTS tika.\n\n\n\n---\n\n\n\nInternal reference: DOV-8591\nType: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027))\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 2.3.0\nFirst fixed revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nDiscovery date: 2026-01-07\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: strokep@yeswehack\nCVE: CVE-2026-0394\nCVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)\n\nDetails:\nauth: Path traversal in passwd-file passdb using `%d` (domain) escapes base directory and opens `/etc/passwd`Pre-auth \npath traversal in passwd-file passdb using `%d` (domain) escapes base directory and opens `/etc/passwd`. When dovecot \nhas been configured to use per-domain passwd files, and they are placed one path component above /etc, or slash has \nbeen added to allowed characters, path traversal can happen if the domain component is directory partial.\n\nRisk:\nThis allows inadvertently reading /etc/passwd (or some other path which ends with passwd). If this file contains \npasswords, it can be used to authenticate wrongly, or if this is userdb, it can unexpectly make system users appear \nvalid users.  No publicly available exploits are known.\n\nSolution:\nUpgrade to fixed version, or use different authentication scheme that does not rely on paths. Alternatively you can \nalso ensure that the per-domain passwd files are in some other location, such as /etc/dovecot/auth/%d.\n\n\n\n---\n\n\n\nInternal reference: DOV-8775\nType: CWE-90 (Improper Neutralization of Special Elements used in an LDAP Query (\u0027LDAP Injection\u0027))\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4\nDiscovery date: 2026-02-20\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: cookiejack15@yeswehack\nCVE: CVE-2026-27860\nCVSS: 3.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N)\n\nDetails:\nv2.4/v3.1 regression: auth-ldap is not escaping usernames. If auth_username_chars is empty, it is possible to inject \narbitrary LDAP filter to Dovecot\u0027s LDAP authentication.\n\nRisk:\nThis leads to potentially bypassing restrictions and allows probing of LDAP structure. No publicly available exploits \nare known.\n\nSolution:\nDo not clear out auth_username_chars, or install fixed version.\n\n\n\n---\n\n\n\nInternal reference: DOV-8781\nType: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command (\u0027SQL Injection\u0027))\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4\nDiscovery date: 2026-02-23\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: whisperer@yeswehack\nCVE: CVE-2026-24031\nCVSS: 7.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L)\n\nDetails:\nv2.4/v3.1 regression: SQL injection allows bypassing authentication. Dovecot SQL based authentication can be bypassed \nwhen auth_username_chars is cleared by admin.\n\nRisk:\nThis vulnerability allows bypassing authentication for any user and user enumeration. No publicly available exploits \nare known.\n\nSolution:\nDo not clear auth_username_chars. If this is not possible, install latest fixed version.\n\n\n\n---\n\n\n\nInternal reference: DOV-8787\nType: CWE-400 (Uncontrolled Resource Consumption)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 3.0.2, OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4\nDiscovery date: 2026-02-24\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: djvirus@yeswehack\nCVE: CVE-2026-27859\nCVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)\n\nDetails:\nv3.0.2+ regression: Message headers MIME parameter parsing can cause excessive CPU usage. A mail message containing \nexcessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU.\n\nRisk:\nA suitably formatted mail message causes mail delivery process to consume large amounts of CPU time. No publicly \navailable exploits are known.\n\nSolution:\nUse MTA capabilities to limit RFC 2231 MIME parameters in mail messages, or upgrade to fixed version where the \nprocessing is limited.\n\n\n\n---\n\n\n\nInternal reference: DOV-8816\nType: CWE-400 (Uncontrolled Resource Consumption)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 2.3.0\nFirst fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4, OX Dovecot Pro \ncore 2.3.22.1\nDiscovery date: 2026-02-27\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: whisperer@yeswehack\nCVE: CVE-2026-27857\nCVSS: 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L)\n\nDetails:\nimap-login: Excessive memory usage DoS. Sending \"NOOP (((...)))\" command with 4000 parenthesis open+close results in \n~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for \nlonger time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and \ncreate 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the \nprocess and its other proxied connections.\n\nRisk:\nAttacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which \nwould likely result in reaching VSZ limit and killing the process and its other proxied connections. No publicly \navailable exploits are known.\n\nSolution:\nInstall fixed version, there is no other remediation.\n\n\n\n---\n\n\n\nInternal reference: DOV-8818\nType: CWE-400 (Uncontrolled Resource Consumption)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 2.3.0, OX Dovecot Pro core 3.1.0, OX Dovecot CE core 2.4.0\nFirst fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4, OX Dovecot Pro \ncore 2.3.22.1\nDiscovery date: 2026-02-28\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: ilyar@yeswehack\nCVE: CVE-2026-27858\nCVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)\n\nDetails:\nmanagesieve-login out-of-memory DoS. Attacker can send a specifically crafted message before authentication that causes \nmanagesieve to allocate large amount of memory.\n\n\nRisk:\nAttacker can force managesieve-login to be unavailable by repeatedly crashing the process. No publicly available \nexploits are known.\n\nSolution:\nProtect access to managesieve protocol, or install fixed version.\n\n\n\n---\n\n\n\nInternal reference: DOV-8830\nType: CWE-287 (Improper Authentication)\nComponent: core\nReport confidence: Confirmed\nSolution status: Fixed by vendor\nLast affected revision: OX Dovecot Pro core 2.3.0\nFirst fixed revision: OX Dovecot Pro core 3.0.5, OX Dovecot CE core 2.4.3, OX Dovecot Pro core 3.1.4, OX Dovecot Pro \ncore 2.3.22.1\nDiscovery date: 2026-03-04\nSolution date: 2026-03-27\nDisclosure date: 2026-03-27\nResearcher credits: bksparajuli@yeswehack\nCVE: CVE-2026-27856\nCVSS: 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)\n\nDetails:\ndoveadm: Credentials verified without timing safety. Doveadm credentials are verified using direct comparison which is \nsusceptible to timing oracle attack. An attacker can use this to determine the configured credentials.\n\nRisk:\nFiguring out the credential will le"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1250",
              "description": "CWE-1250",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-20",
              "description": "CWE-20",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-200",
              "description": "CWE-200",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-22",
              "description": "CWE-22",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-287",
              "description": "CWE-287",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-294",
              "description": "CWE-294",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-400",
              "description": "CWE-400",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-89",
              "description": "CWE-89",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-90",
              "description": "CWE-90",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
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        "dateUpdated": "2026-09-11T11:15:21Z",
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      },
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        },
        {
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        },
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            {
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            {
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              "type": "related"
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            {
              "destId": "CVE-2026-27856",
              "type": "related"
            },
            {
              "destId": "CVE-2026-27857",
              "type": "related"
            },
            {
              "destId": "CVE-2026-27858",
              "type": "related"
            },
            {
              "destId": "CVE-2026-27859",
              "type": "related"
            },
            {
              "destId": "CVE-2026-27860",
              "type": "related"
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          ],
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            "evidenceScore": 9,
            "messageId": "",
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            "sourceFormat": "text/html",
            "sourcePublishedAt": "2026-03-27T08:06:15Z"
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        },
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          "vulnId": "gcve-1988-2026-0235"
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    "assignerShortName": "VULNARCHIVE",
    "datePublished": "2026-09-08T08:13:41Z",
    "dateUpdated": "2026-09-11T11:15:21Z",
    "state": "PUBLISHED",
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}



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Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.