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TI-2026-74163 Aliases CVE-2026-53615

Integer overflow in util-linux libblkid DOS extended partition parsing

Priority LOW 34CWE-190Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · High · High
Fix status
Partial Red Hat: 4 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

util-linux before 2.41.4 contains an integer overflow in libblkid's DOS extended partition parsing in parse_dos_extended(), where the start sector is computed with 32-bit addition (CWE-190). The first two extended boot record entries skip the extended-area bounds checks. A local attacker who gets a crafted DOS extended partition disk image or removable medium probed can wrap the sector address to zero, so libblkid reports a false partition overlapping the MBR. The flaw compromises the integrity of the reported partition metadata.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

util-linux is a random collection of Linux utilities. Before util-linux 2.41.4, `parse_dos_extended()` in `libblkid/src/partitions/dos.c` computes an extended-partition start sector with 32-bit addition and does not apply the extended-area bounds checks to the first two EBR entries. A local attacker who causes a crafted DOS extended-partition disk image or removable medium to be probed can wrap `cur_start + start` to sector zero and cause libblkid to report a false partition overlapping the MBR. This directly compromises the integrity of the reported partition metadata; disk modification or availability loss requires a separate downstream consumer to act on that metadata. This issue is fixed in 2.41.4.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00178 7th percentileScored 2026-11-07
Fix Partial util-linux (util-linux): 2.41.4Red Hat: 2 advisoriesRed Hat: 4 fixed, 7 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
util-linuxutil-linuxbefore 2.41.42.41.4Patch availableCNA
  • util-linux Vendorutil-linux Affected before 2.41.4 Fixed in 2.41.4 Patch available CNA

Remediation

Red Hat fixes util-linux in RHSA-2026:93461 for Red Hat Enterprise Linux AppStream, BaseOS and CodeReady Linux Builder (v. 10), and in RHSA-2026:95365 for Red Hat Cost Management On-Premise 1. Red Hat lists Red Hat Enterprise Linux 7, 8 and 9, Red Hat Hardened Images and Red Hat OpenShift Container Platform 4 and 5 as affected without a fix, with no fix plan available, and lists Red Hat OpenShift AI (RHOAI) as affected without a fix.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA util-linux (util-linux) Fixed in 2.41.4

Red Hat 2 advisories

  • RHSA-2026:95365 Released 2026-11-04 · Red Hat rating Critical
    Red Hat Cost Management On-Premise container image update
    • Red Hat Cost Management On-Premise 1 registry.redhat.io/costmanagement/costmanagement-ui-rhel10
  • RHSA-2026:93461 Released 2026-11-02 · Red Hat rating Important
    util-linux security update
    • Red Hat Enterprise Linux AppStream (v. 10) libblkid-devel-2.40.2-18.el10_2.20, libmount-devel-2.40.2-18.el10_2.20, libuuid-devel-2.40.2-18.el10_2.20 +2
    • Red Hat Enterprise Linux BaseOS (v. 10) libblkid-2.40.2-18.el10_2.20, libfdisk-2.40.2-18.el10_2.20, libmount-2.40.2-18.el10_2.20 +4
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libfdisk-devel-2.40.2-18.el10_2.20, libsmartcols-devel-2.40.2-18.el10_2.20

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Hardened ImagesAffectedNo fix yet
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat Cost Management On-Premise 1Fixed RHSA-2026:95365
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:93461
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:93461
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:93461
Not affected: 1 product
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-14 Threatist record created from CVE-2026-53615
  2. 2026-10-16 CISA SSVC decision points changed
  3. 2026-10-16 Priority changed: MEDIUM → LOW
  4. 2026-10-16 Affected versions changed · Red Hat
  5. 2026-10-16 CVSS score added · Red Hat
  6. 2026-10-30 Affected versions changed · Red Hat
  7. 2026-11-02 Fix available: RHSA-2026:93461 · Red Hat
  8. 2026-11-02 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · Red Hat
  9. 2026-11-05 Fix available: Red Hat Cost Management On-Premise 1 · Red Hat
  10. 2026-11-06 Fix available: RHSA-2026:95365 · Red Hat
  11. 2026-11-06 Affected versions changed · Red Hat

References

Other 5

  • TI-2026-53553 util-linux libmount Privilege Escalation via Failed Mount Helper CVSS 4.0HIGH 8.5
  • TI-2026-73994 Race condition in util-linux mount hook allows privilege escalation CVSS 3.1HIGH 7.0
  • TI-2026-73996 util-linux LIBMOUNT_FORCE_MOUNT2 allows nosuid and noexec bypass CVSS 3.1HIGH 7.0
  • TI-2026-73995 Race condition in util-linux mount lets local users gain root CVSS 3.1HIGH 7.0
  • TI-2025-12886 Util-linux: util-linux: heap buffer overread in setpwnam() when processing 256-byte usernames CVSS 3.1MEDIUM 6.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences