CVE-2026-52930: ipc/shm: serialize orphan cleanup with shm_nattch updates
Vulnerability summary
CVE-2026-52930 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.8% 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 37 · Related 37Timeline
- 24-06-2026PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ipc/shm: serialize orphan cleanup with shm_nattch updates shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that does not serialize all fields tested by shm_may_destroy(). In particular, shm_nattch is updated while holding shm_perm.lock, and attach paths can do that without holding the rwsem. Do not decide that an orphaned segment is unused before taking the object lock. Move the shm_may_destroy() check under shm_perm.lock, matching the other destroy paths, and unlock the segment when it no longer qualifies for removal.
CVSS metrics
3 scores · 3 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
EPSS trend
Probability
0.12%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.12% 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 causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu168 products
- linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-146.146 | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1066.69 | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Chainguard6 products
- linux-azure-6.18< 6.18.38-r0
- linux-gcp-6.18< 6.18.38-r0
- linux-gcp-6.18-bootc-boot-installed< 6.18.38-r0
- linux-qemu-6.18< 6.18.38-r0
- linux-qemu-6.18-bootc-boot-installed< 6.18.38-r0
Linux2 products
- linux≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < b1e9aef48e4d8a0c1b54fb913077b0824ed7d650 | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < 92cda2593cf2ed25b0e9d78e5e6d8303bba1a064 | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < 1f0d01e35dbb228084d5187212e32c91a30dcbeb | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < 6560be3f6a5bb84f006f184f0c966747bb58e1a3 | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < b5107b4ce3ad45fcf369ee2058c8910620f4b5a8 | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < db752ebfdaf2c7f27cd9690ef48b616af068319c | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < 030bbc857bd51d4b25a90d931d3f8775ef22823a | ≥ 4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d, < 2e5c6f4fd4001562781e99bbfc7f1f0127187542 | 3.1
- linux_kernel≥ 3.1, < 5.10.259 | ≥ 5.11, < 5.15.210 | ≥ 5.16, < 6.1.176 | ≥ 6.2, < 6.6.143 | ≥ 6.7, < 6.12.94 | ≥ 6.13, < 6.18.36 | ≥ 6.19, < 7.0.13 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4 | 7.1:rc5 | 7.1:rc6 | 7.1:rc7
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.13-1
4 vendors · 177 products
