VulnerabilityPublished 25 Apr 2026Updated 21 Oct 2026

CVE-2026-31677: Linux kernel · crypto: af_alg – limit RX SG extraction by receive buffer budget

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 9bf3e6ccfdcfe56ae3190d1ae987dacf1cfef4f9 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:30 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9bf3e6ccfdcfe56ae3190d1ae987dacf1cfef4f9, 8eceab19eba9dcbfd2a0daec72e1bf48aa100170, 7e345de2e69475430af85e09210795d8eb8e719c +2

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ e870456d8e7c8d57c059ea479b5aadbb55ff4c3a, < 9bf3e6ccfdcfe56ae3190d1ae987dacf1cfef4f9	Fixed in 9bf3e6ccfdcfe56ae3190d1ae987dacf1cfef4f9
LinuxLinux	Affected ≥ e870456d8e7c8d57c059ea479b5aadbb55ff4c3a, < 8eceab19eba9dcbfd2a0daec72e1bf48aa100170	Fixed in 8eceab19eba9dcbfd2a0daec72e1bf48aa100170
LinuxLinux	Affected ≥ e870456d8e7c8d57c059ea479b5aadbb55ff4c3a, < 7e345de2e69475430af85e09210795d8eb8e719c	Fixed in 7e345de2e69475430af85e09210795d8eb8e719c
LinuxLinux	Affected ≥ e870456d8e7c8d57c059ea479b5aadbb55ff4c3a, < 07c6f6ffe29009426f0bd4d3cfbb6308b8ea8453	Fixed in 07c6f6ffe29009426f0bd4d3cfbb6308b8ea8453
LinuxLinux	Affected ≥ e870456d8e7c8d57c059ea479b5aadbb55ff4c3a, < 4a264b2614c73c96666e196bbabe0cead52bdba7	Fixed in 4a264b2614c73c96666e196bbabe0cead52bdba7
LinuxLinux	Affected =4.14	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - limit RX SG extraction by receive buffer budget Make af_alg_get_rsgl() limit each RX scatterlist extraction to the remaining receive buffer budget. af_alg_get_rsgl() currently uses af_alg_readable() only as a gate before extracting data into the RX scatterlist. Limit each extraction to the remaining af_alg_rcvbuf(sk) budget so that receive-side accounting matches the amount of data attached to the request. If skcipher cannot obtain enough RX space for at least one chunk while more data remains to be processed, reject the recvmsg call instead of rounding the request length down to zero.

References

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