I don’t have live tool access in this turn to pull the very latest updates, but here’s a concise summary based on the most recent publicly reported information up to now about CVE-2026-31431.
Core issue
- CVE-2026-31431 affects the Linux kernel’s crypto subsystem, specifically the algif_aead path, involving how associated data is handled when operating with AEAD (Authenticated Encryption with Associated Data). The vulnerability relates to an out-of-place vs in-place operation decision that could lead to unintended behavior in cryptographic processing. Patch notes indicate the fix reverts to operating out-of-place and simplifies AD copying to avoid the problematic in-place path. CVSS and exploitation details have been reported by multiple security trackers, with a notable focus on local‑privilege and cryptographic operation exposure risks. For specifics on the technical root cause and patch rationale, see the kernel commit and advisory communications from kernel.org and CVE databases.[1][2][3]
Known impact and exploitation
- The vulnerability has been described as having local attack potential with high impact on confidentiality, integrity, and availability in affected configurations, particularly where untrusted users have access to cryptographic operations. There have been reports of proof-of-concept exploits and some mentions of active exploitation in certain advisories and threat feeds, though the degree of real-world exploitation varies by environment and patch status. The CVSS vector commonly cited includes local access prerequisites with high impact metrics. For concrete CVSS values and affected products, refer to the NVD entry and vendor advisories.[2][3][1]
Mitigations and patching
- Patches exist across multiple kernel series (including recent long-term support releases and stable lines). Applied patches adjust the algif_aead handling to avoid in-place AD copying and mitigate the flaw. In the meantime, mitigations cited in advisories include restricting cryptographic socket operations for untrusted users and monitoring for exploitation attempts targeting crypto subsystems. As always, apply the official kernel updates from your distribution promptly, and validate that affected systems have received the patch or compensation workarounds.[1][2]
Timeline highlights (high level)
- CVE-2026-31431 was assigned in April 2026 with initial advisories and patches released shortly thereafter. Subsequent security bulletins from various vendors and security feeds tracked patch availability and exploit activity, with broader coverage in late April and May 2026. For precise dates and vendor-specific advisories, consult the CVE/NVD entries and vendor security pages.[3][2][1]
What you should do now (London-based environment)
- If you operate Linux servers, check your kernel version and ensure you’re running a patched release (as provided by your distribution). Prioritize systems that perform cryptographic operations exposed to local untrusted users. Apply patches from kernel.org or your distro’s security advisories promptly.[2]
- Audit for any untrusted local users with access to crypto sockets or algif_aead interfaces and limit such access if possible until patches are confirmed deployed.[1]
- Monitor security feeds for exploit indicators (PoCs, weaponized variants) and ensure your intrusion detection rules are updated to flag suspicious crypto‑subsystem activity.[1]
If you’d like, I can assemble a quick checklist tailored to your environment (e.g., Ubuntu/Dedora/RHEL variants, cloud vs on-prem, containerized workloads) and, with your permission, guide you through verifying patch status and applying updates. I can also pull the most up-to-date advisories for your specific distro if you share which systems you’re running.
Sources
In the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly. CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
feedly.comSCS Computing Facilities is beginning a multi-phased project to migrate all SCS managed Windows computers from the SCS Windows domain, to the Andrew Windows domain.
computing.cs.cmu.eduComprehensive vulnerability database for your open source projects and dependencies.
osv.devOn this page, you can view the details of a specific CVE through an interface that correlates various data sources.
www.redhotcyber.com1. #### CVE-2026-31431 IDCVE-2026-31431 SažetakIn the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly. … CVSSBase:...
cve.cert.hrIn the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly.
cve.akaoma.comNVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed. CVSS 4.0 Severity and Vector Strings: NIST: NVD N/A NVD assessment not yet provided. … Mailing List Patch http://www.openwall.com/lists/oss-security/2026/04/30/16CVE Mailing List Patch http://www.openwall.com/lists/oss-security/2026/04/30/17CVE … Patch
nvd.nist.govNVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed. CVSS 4.0 Severity and Vector Strings: NIST: NVD N/A NVD assessment not yet provided. … Patch https://git.kernel.org/stable/c/3115af9644c342b356f3f07a4dd1c8905cd9a6fckernel.org Patch … Patch https://git.kernel.org/stable/c/961cfa271a918ad4ae452420e7c30314900287
nvd.nist.govIn the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly.
www.tenable.com