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Fencer Vulns
high 8.4

CVE-2026-0861 json

Integer overflow in memalign leads to heap corruption

published 2026-01-14 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-2441

cvss
8.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

Passing too large an alignment to the memalign suite of functions (memalign, posix_memalign, aligned_alloc) in the GNU C Library version 2.30 to 2.42 may result in an integer overflow, which could consequently result in a heap corruption.

Note that the attacker must have control over both, the size as well as the alignment arguments of the memalign function to be able to exploit this. The size parameter must be close enough to PTRDIFF_MAX so as to overflow size_t along with the large alignment argument. This limits the malicious inputs for the alignment for memalign to the range [1<<62+ 1, 1<<63] and exactly 1<<63 for posix_memalign and aligned_alloc.

Typically the alignment argument passed to such functions is a known constrained quantity (e.g. page size, block size, struct sizes) and is not attacker controlled, because of which this may not be easily exploitable in practice. An application bug could potentially result in the input alignment being too large, e.g. due to a different buffer overflow or integer overflow in the application or its dependent libraries, but that is again an uncommon usage pattern given typical sources of alignments.

Patch / fix

  • glibc Debian 12 2.36-9+deb12u14
  • glibc Debian 13 2.41-12+deb13u2
  • glibc Debian 14 2.42-8

debian advisories DEBIAN-CVE-2026-0861

  • glibc Ubuntu 22.04 LTS 2.35-0ubuntu3.13
  • glibc Ubuntu 24.04 LTS 2.39-0ubuntu8.7
  • glibc Ubuntu 25.10 2.42-0ubuntu3.1
  • glibc Ubuntu Pro 20.04 LTS 2.31-0ubuntu9.18+esm1

ubuntu advisories UBUNTU-CVE-2026-0861

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • glibc hummingbird 1 2.42-11.1.hum1
  • glibc32 hummingbird 1 2.42-11.1.hum1
  • glibc-utils hummingbird 1 2.42-11.1.hum1
  • glibc-common hummingbird 1 2.42-11.1.hum1
  • glibc-benchtests hummingbird 1 2.42-11.1.hum1
  • glibc-gconv-extra hummingbird 1 2.42-11.1.hum1
  • glibc-all-langpacks hummingbird 1 2.42-11.1.hum1
  • glibc-locale-source hummingbird 1 2.42-11.1.hum1

red hat advisories RHSA-2026:7316RHSA-2026:2786RHSA-2026:1334

  • glibc SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +9 more 2.31-150300.98.1
  • glibc Linux Micro 6.1 2.38-slfo.1.1_6.1
  • glibc Linux Micro 6.0 2.38-11.1
  • glibc SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 +2 more 2.38-150600.14.40.1
  • glibc SLES 16.0, Linux Micro Extras 6.2, Linux Micro 6.2 +1 more 2.40-160000.3.1
  • glibc-livepatches SLE Live Patching 15 SP7 0.3-150700.10.4.1
  • glibc-livepatches SLE Live Patching 15 SP6 0.3-150600.8.2.1
  • glibc-livepatches SLE Live Patching 15 SP5, SLE Live Patching 15 SP4 0.3-150400.3.11.1

suse advisories SUSE-SU-2026:0896-1SUSE-SU-2026:0827-1SUSE-SU-2026:20536-1SUSE-SU-2026:20527-1SUSE-SU-2026:0499-1SUSE-SU-2026:0371-1

  • glibc openSUSE Tumbleweed 2.43-1.1
  • glibc openSUSE Leap 16.0 2.40-160000.3.1
  • glibc-cross-s390x-src openSUSE Leap 16.0 2.40-160000.3.1
  • glibc-cross-aarch64-src openSUSE Leap 16.0 2.40-160000.3.1
  • glibc-cross-ppc64le-src openSUSE Leap 16.0 2.40-160000.3.1
  • glibc-cross-riscv64-src openSUSE Leap 16.0 2.40-160000.3.1

opensuse advisories openSUSE-SU-2026:10662-1openSUSE-SU-2026:20133-1

  • glibc AlmaLinux 9 2.34-231.el9_7.10
  • nscd AlmaLinux 9 2.34-231.el9_7.10
  • libnsl AlmaLinux 9 2.34-231.el9_7.10
  • nss_db AlmaLinux 9 2.34-231.el9_7.10
  • nss_hesiod AlmaLinux 9 2.34-231.el9_7.10
  • glibc-utils AlmaLinux 9 2.34-231.el9_7.10
  • glibc-common AlmaLinux 9 2.34-231.el9_7.10
  • glibc-benchtests AlmaLinux 9 2.34-231.el9_7.10

almalinux advisories ALSA-2026:2786

  • glibc Rocky Linux 9 2.34-231.el9_7.10
  • glibc Rocky Linux 10 2.39-58.el10_1.7

rocky linux advisories RLSA-2026:2786RLSA-2026:1334

  • glibc Azure Linux 3.0 2.38-18
  • glibc CBL-Mariner 2.0 2.35-9

azure linux advisories AZL-74547AZL-74636

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-0861 updated cvss 8.1

glibc: Integer overflow in memalign leads to heap corruption

  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.18 cert-manager/cert-manager-operator-rhel9 1789029076, cert-manager/jetstack-cert-manager-rhel9 1791459711, cert-manager/cert-manager-istio-csr-rhel9 1791459759, cert-manager/cert-manager-operator-bundle 1791966259, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791459707
    fixed: vendor fix RHSA-2026:82354
  • Red Hat Cost Management 4 costmanagement 1770836349
    fixed: vendor fix RHSA-2026:3228
  • Red Hat Ceph Storage 8 rhceph 1774002867
    fixed: vendor fix RHSA-2026:5606
  • Red Hat Discovery 2 discovery 1773273070, discovery 1773273243
    fixed: vendor fix RHSA-2026:4501
  • Red Hat Enterprise Linux AppStream (v. 10) glibc-utils 2.39-58.el10_1.7, glibc-locale-source 2.39-58.el10_1.7
    fixed: vendor fix RHSA-2026:1334
  • Red Hat Enterprise Linux BaseOS (v. 9) glibc 2.34-231.el9_7.10
    fixed: vendor fix RHSA-2026:2786
  • Red Hat Enterprise Linux BaseOS (v. 10) glibc 2.39-58.el10_1.7, libnsl 2.39-58.el10_1.7, glibc-common 2.39-58.el10_1.7, glibc-gconv-extra 2.39-58.el10_1.7, glibc-all-langpacks 2.39-58.el10_1.7, glibc-minimal-langpack 2.39-58.el10_1.7
    fixed: vendor fix RHSA-2026:1334
show 6 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) glibc-static 2.34-231.el9_7.10
    fixed: vendor fix RHSA-2026:2786
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) nss_db 2.39-58.el10_1.7, nss_hesiod 2.39-58.el10_1.7, glibc-benchtests 2.39-58.el10_1.7
    fixed: vendor fix RHSA-2026:1334
  • Red Hat Hardened Images glibc 2.42-11.1.hum1, glibc32 2.42-11.1.hum1, glibc-utils 2.42-11.1.hum1, glibc-common 2.42-11.1.hum1, glibc-benchtests 2.42-11.1.hum1, glibc-gconv-extra 2.42-11.1.hum1, +5 more
    fixed: vendor fix RHSA-2026:7316
  • Red Hat Insights proxy 1.5 insights-proxy 1773685509
    fixed: vendor fix RHSA-2026:4655
  • Red Hat Update Infrastructure 5 rhui5 1773668803, rhui5 1773670073, rhui5 1773670137, rhui5 1773672059
    fixed: vendor fix RHSA-2026:4943
  • Red Hat Cost Management 4 costmanagement 1770837277 Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, compat-glibc, glibc-common Red Hat Enterprise Linux 7 nscd, glibc, glibc-utils, compat-glibc, glibc-common Red Hat Enterprise Linux 8 nscd, glibc, libnsl, nss_db, nss_hesiod, glibc-utils, +7 more Red Hat Enterprise Linux AppStream (v. 9) glibc-utils 2.34-231.el9_7.10, glibc-locale-source 2.34-231.el9_7.10 Red Hat Enterprise Linux BaseOS (v. 9) nscd 2.34-231.el9_7.10, libnsl 2.34-231.el9_7.10, glibc-common 2.34-231.el9_7.10, glibc-gconv-extra 2.34-231.el9_7.10, glibc-all-langpacks 2.34-231.el9_7.10, glibc-minimal-langpack 2.34-231.el9_7.10
    +3 more products
    Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) nss_db 2.34-231.el9_7.10, nss_hesiod 2.34-231.el9_7.10, glibc-benchtests 2.34-231.el9_7.10 Red Hat Hardened Images libnsl 2.42-11.1.hum1, nss_db 2.42-11.1.hum1, nss_hesiod 2.42-11.1.hum1, compat-libpthread-nonshared 2.42-11.1.hum1 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
6 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • sourceware.org https://sourceware.org/bugzilla/show_bug.cgi?id=33796 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.4 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 8.4 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • The GNU C Library glibc

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.