CVE-2026-45991: Linux kernel · udf: fix partition descriptor append bookkeeping
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e8474cfbac9ada2cdaa4eaedec22aadfa0f58559 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in e8474cfbac9ada2cdaa4eaedec22aadfa0f58559, b5597bb83fc37b5b5da74a4453fa920b932cf39a, ad3c0c4400686f6f37b382aaa48fac2b9aefccbe +6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: udf: fix partition descriptor append bookkeeping Mounting a crafted UDF image with repeated partition descriptors can trigger a heap out-of-bounds write in part_descs_loc[]. handle_partition_descriptor() deduplicates entries by partition number, but appended slots never record partnum. As a result duplicate Partition Descriptors are appended repeatedly and num_part_descs keeps growing. Once the table is full, the growth path still sizes the allocation from partnum even though inserts are indexed by num_part_descs. If partnum is already aligned to PART_DESC_ALLOC_STEP, ALIGN(partnum, step) can keep the old capacity and the next append writes past the end of the table. Store partnum in the appended slot and size growth from the next append count so deduplication and capacity tracking follow the same model.
References
- git.kernel.org/stable/c/ad3c0c4400686f6f37b382aaa48fac2b9aefccbe (opens in a new tab)
- git.kernel.org/stable/c/68013a9bd4c01acd42073715f00e1a1992f089ee (opens in a new tab)
- git.kernel.org/stable/c/e8474cfbac9ada2cdaa4eaedec22aadfa0f58559 (opens in a new tab)
- git.kernel.org/stable/c/058b451b1039f056d1362c4fec2229e522366ab0 (opens in a new tab)
- git.kernel.org/stable/c/b5597bb83fc37b5b5da74a4453fa920b932cf39a (opens in a new tab)
- git.kernel.org/stable/c/73df74544b55241dca5dd788523e6f5f10bd2b9b (opens in a new tab)
- git.kernel.org/stable/c/08fa5d818e5bf53c7ca234d88ba334f32004e9b6 (opens in a new tab)
- git.kernel.org/stable/c/08841b06fa64d8edbd1a21ca6e613420c90cc4b8 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)