CVE-2025-21635: rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy
Vulnerability summary
CVE-2025-21635 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.9% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 25 · Related 27Timeline
- 19-01-2025PublishedVulnerability first disclosed.
- 30-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The per-netns structure can be obtained from the table->data using container_of(), then the 'net' one can be retrieved from the listen socket (if available).
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.25%
Chance of exploitation in the next 30 days
Percentile
17%
Versus all other CVEs
30-day change
Increase +0.07 pp
From 0.18% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu135 products
- linuxAll versions (No fix recorded) | < 6.8.0-60.63
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1029.31
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ c6a58ffed53612be86b758df1cdb0b0f4305e9cb, < 6f353c2230c199f343406c08482940ec5d8ba89c | ≥ c6a58ffed53612be86b758df1cdb0b0f4305e9cb, < 33b3e09a489a31b30342b77cc55290f025d95c7e | ≥ c6a58ffed53612be86b758df1cdb0b0f4305e9cb, < de8d6de0ee27be4b2b1e5b06f04aeacbabbba492 | ≥ c6a58ffed53612be86b758df1cdb0b0f4305e9cb, < 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c | 4.6
- linux_kernel≥ 4.6, < 6.12.10 | 6.13:rc1 | 6.13:rc2 | 6.13:rc3 | 6.13:rc4 | 6.13:rc5 | 6.13:rc6
Debian1 product
- linuxAll versions (No fix recorded) | < 6.12.10-1
3 vendors · 138 products
