CVE-2026-45991

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-27. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

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.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

May 27, 2026

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Jun 3, 2026
No patch confirmed yet.
generic

udf: fix partition descriptor append bookkeeping - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b5597bb83fc37b5b5da74a4453fa920b932cf39a
generic

udf: fix partition descriptor append bookkeeping - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/08fa5d818e5bf53c7ca234d88ba334f32004e9b6
generic

udf: fix partition descriptor append bookkeeping - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/08841b06fa64d8edbd1a21ca6e613420c90cc4b8
generic

udf: fix partition descriptor append bookkeeping - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/058b451b1039f056d1362c4fec2229e522366ab0

Vendor Advisories for CVE-2026-45991(5)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(24)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oem-7.0 (7.0.0-1008.8) @ resolute2026-08-25ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1014.14) @ resolute2026-08-25ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1013.13) @ resolute2026-08-25ubuntu
ubuntulinux-tools-realtime-hwe-22.04 (6.8.1-1056.57~22.04.2) @ jammy2026-08-25ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-08-25ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-08-25ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-08-25ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-08-25ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-08-25ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-25ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-08-25ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-08-25ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-08-25ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-08-25ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-08-25ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-08-25ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1033.34) @ noble2026-08-25ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-08-25ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-27.27) @ resolute2026-08-25ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-08-25ubuntu
redhatkernel-0:5.14.0-687.41.1.el9_82026-08-20redhat
redhatkernel-0:6.12.0-211.49.1.el10_22026-08-20redhat
redhatkernel-rt-0:4.18.0-553.155.1.rt7.496.el8_102026-08-12redhat
redhatkernel-0:4.18.0-553.155.1.el8_102026-08-12redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)6.1.176-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.88-1~bpo12+1 (21 versions)6.12.88-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.4-1~bpo13+1 (131 versions)7.0.4-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(21)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 5× in last 7d / 86× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 278 total refreshes for this CVE.

  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-02 14:12 UTCEPSS rescore
  3. 2026-09-01 13:54 UTCEPSS rescore
  4. 2026-08-30 19:17 UTCEPSS rescore
  5. 2026-08-30 01:22 UTCEPSS rescore
  6. 2026-08-28 21:41 UTCEPSS rescore
  7. 2026-08-27 14:25 UTCEPSS rescore
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-25 05:33 UTCEG score recompute
  11. 2026-08-25 05:33 UTCVendor advisory
  12. 2026-08-25 05:32 UTCGHSA enrichment
  13. 2026-08-23 15:23 UTCEG score recompute
  14. 2026-08-23 15:23 UTCVendor advisory
  15. 2026-08-23 15:23 UTCGHSA enrichment
  16. 2026-08-23 00:19 UTCEPSS rescore
  17. 2026-08-21 23:49 UTCEPSS rescore
  18. 2026-08-21 20:45 UTCVendor advisory
  19. 2026-08-21 20:44 UTCGHSA enrichment
  20. 2026-08-21 01:43 UTCEG score recompute
  21. 2026-08-21 01:43 UTCVendor advisory
  22. 2026-08-21 01:43 UTCGHSA enrichment
  23. 2026-08-20 22:55 UTCEPSS rescore
  24. 2026-08-20 11:40 UTCEG score recompute
  25. 2026-08-20 11:40 UTCVendor advisory
Show 75 more
  1. 2026-08-20 11:40 UTCGHSA enrichment
  2. 2026-08-19 17:04 UTCEPSS rescore
  3. 2026-08-18 13:48 UTCEPSS rescore
  4. 2026-08-17 13:47 UTCEPSS rescore
  5. 2026-08-17 09:19 UTCVendor advisory
  6. 2026-08-17 09:19 UTCGHSA enrichment
  7. 2026-08-16 15:37 UTCEG score recompute
  8. 2026-08-16 15:37 UTCVendor advisory
  9. 2026-08-16 15:37 UTCGHSA enrichment
  10. 2026-08-16 14:56 UTCEPSS rescore
  11. 2026-08-16 02:52 UTCEG score recompute
  12. 2026-08-16 02:52 UTCVendor advisory
  13. 2026-08-16 02:52 UTCGHSA enrichment
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 01:30 UTCEPSS rescore
  16. 2026-08-15 00:33 UTCVendor advisory
  17. 2026-08-15 00:33 UTCGHSA enrichment
  18. 2026-08-14 13:01 UTCVendor advisory
  19. 2026-08-14 13:01 UTCGHSA enrichment
  20. 2026-08-14 01:29 UTCVendor advisory
  21. 2026-08-14 01:29 UTCGHSA enrichment
  22. 2026-08-13 01:26 UTCVendor advisory
  23. 2026-08-13 01:26 UTCGHSA enrichment
  24. 2026-08-12 13:54 UTCEG score recompute
  25. 2026-08-12 13:54 UTCVendor advisory
  26. 2026-08-12 13:54 UTCGHSA enrichment
  27. 2026-08-12 13:51 UTCEPSS rescore
  28. 2026-08-12 01:07 UTCEG score recompute
  29. 2026-08-12 01:07 UTCVendor advisory
  30. 2026-08-12 01:07 UTCGHSA enrichment
  31. 2026-08-11 13:36 UTCVendor advisory
  32. 2026-08-11 13:36 UTCGHSA enrichment
  33. 2026-08-11 00:14 UTCEG score recompute
  34. 2026-08-11 00:14 UTCVendor advisory
  35. 2026-08-11 00:14 UTCGHSA enrichment
  36. 2026-08-11 00:00 UTCEPSS rescore
  37. 2026-08-10 09:26 UTCVendor advisory
  38. 2026-08-10 09:26 UTCGHSA enrichment
  39. 2026-08-09 21:54 UTCEG score recompute
  40. 2026-08-09 21:54 UTCVendor advisory
  41. 2026-08-09 21:54 UTCGHSA enrichment
  42. 2026-08-09 13:46 UTCEPSS rescore
  43. 2026-08-09 10:22 UTCVendor advisory
  44. 2026-08-09 10:22 UTCGHSA enrichment
  45. 2026-08-08 22:47 UTCEG score recompute
  46. 2026-08-08 22:47 UTCVendor advisory
  47. 2026-08-08 22:47 UTCGHSA enrichment
  48. 2026-08-08 16:37 UTCEPSS rescore
  49. 2026-08-08 11:14 UTCVendor advisory
  50. 2026-08-08 11:14 UTCGHSA enrichment
  51. 2026-08-07 23:42 UTCEG score recompute
  52. 2026-08-07 23:42 UTCVendor advisory
  53. 2026-08-07 23:42 UTCGHSA enrichment
  54. 2026-08-07 12:11 UTCVendor advisory
  55. 2026-08-07 12:11 UTCGHSA enrichment
  56. 2026-08-07 00:29 UTCEG score recompute
  57. 2026-08-07 00:29 UTCVendor advisory
  58. 2026-08-07 00:29 UTCGHSA enrichment
  59. 2026-08-06 13:47 UTCEPSS rescore
  60. 2026-08-06 12:48 UTCVendor advisory
  61. 2026-08-06 12:48 UTCGHSA enrichment
  62. 2026-08-06 01:14 UTCEG score recompute
  63. 2026-08-06 01:14 UTCVendor advisory
  64. 2026-08-06 01:14 UTCGHSA enrichment
  65. 2026-08-05 19:17 UTCEPSS rescore
  66. 2026-08-05 13:43 UTCEG score recompute
  67. 2026-08-05 13:43 UTCVendor advisory
  68. 2026-08-05 13:43 UTCGHSA enrichment
  69. 2026-08-04 15:10 UTCEPSS rescore
  70. 2026-08-04 10:39 UTCEPSS rescore
  71. 2026-08-04 04:00 UTCVendor advisory
  72. 2026-08-04 04:00 UTCGHSA enrichment
  73. 2026-08-03 16:28 UTCEG score recompute
  74. 2026-08-03 16:28 UTCVendor advisory
  75. 2026-08-03 16:28 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-45991?
CVE-2026-45991 is a high vulnerability published on May 27, 2026. 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 partdescsloc[]. handlepartitiondescriptor() deduplicates entries by…
When was CVE-2026-45991 disclosed?
CVE-2026-45991 was first published in the National Vulnerability Database on May 27, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45991 actively exploited?
CVE-2026-45991 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.6% of all scored CVEs.
What is the CVSS score of CVE-2026-45991?
CVE-2026-45991 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-45991?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45991, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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