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NVD / CVE Program· CNA Linux

CVE-2023-53728: posix-timers: Ensure timer ID search-loop limit is valid

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
  • Fixed version: Linux Linux 322377cc909defcca9451487484845e7e1d20d1b, 37175e25edf7cc0d5a2cd2c2a1cbe2dcbf4a1937, 6a0ac84501b4fec73a1a823c55cf13584c43f418.

Low priority for now. Upgrade to Linux Linux 322377cc909defcca9451487484845e7e1d20d1b, 37175e25edf7cc0d5a2cd2c2a1cbe2dcbf4a1937, 6a0ac84501b4fec73a1a823c55cf13584c43f418 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: posix-timers: Ensure timer ID search-loop limit is valid posix_timer_add() tries to allocate a posix timer ID by starting from the cached ID which was stored by the last successful allocation. This is done in a loop searching the ID space for a free slot one by one. The loop has to terminate when the search wrapped around to the starting point. But that's racy vs. establishing the starting point. That is read out lockless, which leads to the following problem: CPU0 CPU1 posix_timer_add() start = sig->posix_timer_id; lock(hash_lock); ... posix_timer_add() if (++sig->posix_timer_id < 0) start = sig->posix_timer_id; sig->posix_timer_id = 0; So CPU1 can observe a negative start value, i.e. -1, and the loop break never happens because the condition can never be true: if (sig->posix_timer_id == start) break; While this is unlikely to ever turn into an endless loop as the ID space is huge (INT_MAX), the racy read of the start value caught the attention of KCSAN and Dmitry unearthed that incorrectness. Rewrite it so that all id operations are under the hash lock.

—No exploit Fix available
Published
Oct 22, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 11th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.10affected
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 8dc52c200b889bc1cb34288fbf623d4ff381d2aeaffected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 9ea26a8494a0a9337e7415eafd6f3ed940327dc5affected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 8ad6679a5bb97cdb3e14942729292b4bfcc0e223affected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 322377cc909defcca9451487484845e7e1d20d1baffected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before ef535e0315afd098c4beb1da364847eca4b56a20affected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 6a0ac84501b4fec73a1a823c55cf13584c43f418affected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 37175e25edf7cc0d5a2cd2c2a1cbe2dcbf4a1937affected · git
    • 5ed67f05f66c41e39880a6d61358438a25f9fee5 and later · before 8ce8849dd1e78dadcee0ec9acbd259d239b7069faffected · git
    • before 3.10not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.112-16.1.112-1
Debian:13linuxbefore 6.4.11-16.4.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2022-50581Oct 22, 2025 · hfs: fix OOB Read in __hfs_brec_find
    31Monitor
  • ← EarlierCVE-2022-50582Oct 22, 2025 · regulator: core: Prevent integer underflow
    0Monitor
  • Later →CVE-2023-53692Oct 22, 2025 · ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux322377cc909defcca9451487484845e7e1d20d1bVendor (CNA)
Linux Linux37175e25edf7cc0d5a2cd2c2a1cbe2dcbf4a1937Vendor (CNA)
Linux Linux6a0ac84501b4fec73a1a823c55cf13584c43f418Vendor (CNA)
Linux Linux8ad6679a5bb97cdb3e14942729292b4bfcc0e223Vendor (CNA)
Linux Linux8ce8849dd1e78dadcee0ec9acbd259d239b7069fVendor (CNA)
Linux Linux8dc52c200b889bc1cb34288fbf623d4ff381d2aeVendor (CNA)
Linux Linux9ea26a8494a0a9337e7415eafd6f3ed940327dc5Vendor (CNA)
Linux Linuxef535e0315afd098c4beb1da364847eca4b56a20Vendor (CNA)
debian:linux6.1.112-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records