CVE-2025-39964 (GCVE-0-2025-39964)
Vulnerability from cvelistv5 – Published: 2025-10-13 13:48 – Updated: 2026-09-19 03:56- CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce
(git)
Affected: 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < e4c1ec11132ec466f7362a95f36a506ce4dc08c9 (git) Affected: 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 (git) Affected: 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < 7c4491b5644e3a3708f3dbd7591be0a570135b84 (git) Affected: 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < 9aee87da5572b3a14075f501752e209801160d3d (git) Affected: 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < 45bcf60fe49b37daab1acee57b27211ad1574042 (git) Affected: 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 , < 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 (git) |
guessed | |
| Linux | Linux |
Affected:
2.6.38
Unaffected: 0 , < 2.6.38 (semver) Unaffected: 5.10.245 , ≤ 5.10.* (semver) Unaffected: 5.15.194 , ≤ 5.15.* (semver) Unaffected: 6.1.154 , ≤ 6.1.* (semver) Unaffected: 6.6.108 , ≤ 6.6.* (semver) Unaffected: 6.12.49 , ≤ 6.12.* (semver) Unaffected: 6.16.9 , ≤ 6.16.* (semver) Unaffected: 6.17 , ≤ * (original_commit_for_fix) |
guessed | |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
guessed | |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
guessed | |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
guessed |
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
Exploited: Yes
Timestamps
Scope
Evidence
Type: Vendor Report
Signal: Successful Exploitation
Confidence: 80%
Source: cisa-kev
Details
| Cwes | CWE-362 |
|---|---|
| Feed | CISA Known Exploited Vulnerabilities Catalog |
| Product | Kernel |
| Due Date | 2026-09-21 |
| Date Added | 2026-09-18 |
| Vendorproject | Linux |
| Vulnerabilityname | Linux Kernel Race Condition Vulnerability |
| Knownransomwarecampaignuse | Unknown |
References
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
Exploited: Yes
Timestamps
Scope
Evidence
Type: Public Report
Signal: Successful Exploitation
Confidence: 70%
Source: previdian
Details
| Feed | Previdian (previdian.com) |
|---|---|
| Title | crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg |
| Cve Id | CVE-2025-39964 |
| Vendor | Linux |
| Ghsa Id | GHSA-WR5G-MFHW-RPFJ |
| Product | Linux |
| Added Date | 2026-09-18T14:30:42.702Z |
| Cvss Score | 7.8 |
| Epss Score | 0.00323 |
| Previous Ids | |
| Cvss Severity | HIGH |
| Virtual Patch | False |
| Cvss Estimated | False |
| Epss Percentile | 0.25599 |
| Used In Malware | unknown |
| Vulnerability Id | CVE-2025-39964 |
| Ahead Of Cisa Kev | None |
| Not Yet In Cisa Kev | False |
References
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"value": "AV:L - The vulnerability is reached through the AF_ALG socket family via `socket()`/`bind()`/`sendmsg()`/`recvmsg()` syscalls, which requires local system access. There is no remote or adjacent-network path to `af_alg_sendmsg()`.\nAC:L - The attacker controls both sides of the race entirely \u2014 two of its own threads on a socket it owns \u2014 and can force writer A to park deterministically in `af_alg_wait_for_wmem()` by sizing `SO_SNDBUF` and filling it, then wake it on demand with its own `recvmsg()`. The error exit that leaves `cur == 0` is triggered at will with a deliberately faulting user buffer, so no condition is outside the attacker\u0027s control.\nPR:L - `alg_create()`, `alg_bind()` and `alg_setkey()` perform no capability checks whatsoever, so any unprivileged local user \u2014 including one inside a container or unprivileged user namespace \u2014 can open, bind and write to an AF_ALG skcipher/aead socket. The required modules are auto-loaded on demand via `MODULE_ALIAS_NETPROTO(AF_ALG)` and `request_module(\"algif-%s\")`.\nUI:N - The attacking process performs every step itself \u2014 socket creation, bind, and the two concurrent `sendmsg()` calls. No victim action or interaction of any kind is needed.\nS:U - The corruption is confined to kernel heap objects (`struct af_alg_tsgl`/scatterlist and adjacent slab memory) within the same security authority. No hypervisor, IOMMU, or other trust boundary is crossed.\nC:H - The out-of-bounds scatterlist entry is fabricated from kernel list pointers and is subsequently handed to the cipher by `skcipher_recvmsg`/`aead_recvmsg` via `af_alg_pull_tsgl()`, so arbitrary kernel memory is encrypted/decrypted and returned to userspace. This yields a kernel memory disclosure primitive, not merely a pointer leak.\nI:H - `memcpy_from_msg(page_address(sg_page(sg)) + sg-\u003eoffset + sg-\u003elength, msg, len)` on the underflowed scatterlist writes attacker-controlled data of attacker-chosen length to an address derived from attacker-influenceable heap contents. Combined with heap grooming of the 4KB tsgl allocations, this is a controlled kernel write suitable for privilege escalation.\nA:H - Dereferencing `page_address(sg_page(sg))` on a bogus page_link, and the later `put_page()` on that fabricated page, reliably produce an oops/panic or page refcount corruption. Any unprivileged user can trigger this repeatedly, crashing the machine."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T12:06:33.126Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/0f28c4adbc4a97437874c9b669fd7958a8c6d6ce"
},
{
"url": "https://git.kernel.org/stable/c/e4c1ec11132ec466f7362a95f36a506ce4dc08c9"
},
{
"url": "https://git.kernel.org/stable/c/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8"
},
{
"url": "https://git.kernel.org/stable/c/7c4491b5644e3a3708f3dbd7591be0a570135b84"
},
{
"url": "https://git.kernel.org/stable/c/9aee87da5572b3a14075f501752e209801160d3d"
},
{
"url": "https://git.kernel.org/stable/c/45bcf60fe49b37daab1acee57b27211ad1574042"
},
{
"url": "https://git.kernel.org/stable/c/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285"
}
],
"title": "crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg",
"x_generator": {
"engine": "bippy-1.2.0"
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}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-39964",
"datePublished": "2025-10-13T13:48:30.334Z",
"dateReserved": "2025-04-16T07:20:57.149Z",
"dateUpdated": "2026-09-19T03:56:17.769Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
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.
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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.