CVE-2023-53825 — kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().
In the Linux kernel, the following vulnerability has been resolved: kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg(). syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720 ("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it by updating kcm_tx_msg(head)->last_skb if partial data is copied so that the following sendmsg() will resume from the skb. However, we cannot know how many bytes were copied when we get the error. Thus, we could mess up the MSG_MORE queue. When kcm_sendmsg() fails for SOCK_DGRAM, we should purge the queue as we do so for UDP by udp_flush_pending_frames(). Even without this change, when the error occurred, the following sendmsg() resumed from a wrong skb and the queue was messed up. However, we have yet to get such a report, and only syzkaller stumbled on it. So, this can be changed safely. Note this does not change SOCK_SEQPACKET behaviour.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+2
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < 21b467735b0888a8daa048f83d3b9b50fdab71ce≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < d4b8f380b0a041ee6a84fdac14127d8fe1dcad7b≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < 1ce8362b4ac6b8e65fd04a22ea37ec776ee1ec5b≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < 2e18493c421428a936946c452461b8e979088f17≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < 55d2e7c1ab8eaa7b62575b8a4194132795d1f9fc≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < e5b28ce127a690f3acc49a6a342e6c9442c9edd6≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < 992b2ac783aad360b98ed9d4686e86176a20f6f1≥ ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 and < a22730b1b4bf437c6bbfdeff5feddf54be4aeada and 1 moreversion 4.6 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.26%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Deferred
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
8 on the record
- git.kernel.org/stable/c/2e18493c421428a936946c452461b8e979088f17
- git.kernel.org/stable/c/1ce8362b4ac6b8e65fd04a22ea37ec776ee1ec5b
- git.kernel.org/stable/c/992b2ac783aad360b98ed9d4686e86176a20f6f1
- git.kernel.org/stable/c/d4b8f380b0a041ee6a84fdac14127d8fe1dcad7b
- git.kernel.org/stable/c/e5b28ce127a690f3acc49a6a342e6c9442c9edd6
- git.kernel.org/stable/c/21b467735b0888a8daa048f83d3b9b50fdab71ce
- git.kernel.org/stable/c/a22730b1b4bf437c6bbfdeff5feddf54be4aeada
- git.kernel.org/stable/c/55d2e7c1ab8eaa7b62575b8a4194132795d1f9fc
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2023-53825 is "kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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