high 7.7

CVE-2026-19499 json

Buffer overflow in strfmon and strfmon_l right-justification padding

published 2026-09-14 55 d ago modified 2026-09-18 51 d ago also EUVD-2026-77675

cvss: 7.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding.

Exploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller.

At the time of publication, no network-facing application impact is known.

Patch / fix

distros 7

debian ubuntu red hat suse opensuse almalinux rocky linux

glibc Debian 14 2.43-5

debian advisories DEBIAN-CVE-2026-19499

glibc Ubuntu 24.04 LTS 2.39-0ubuntu8.9
glibc Ubuntu 26.04 LTS 2.43-2ubuntu2.4

ubuntu advisories UBUNTU-CVE-2026-19499

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 RHEL 10.2 2.39-142.el10_2
libnsl RHEL 10.2 2.39-142.el10_2
nss_db RHEL 10.2 2.39-142.el10_2
nss_hesiod RHEL 10.2 2.39-142.el10_2
glibc-utils RHEL 10.2 2.39-142.el10_2
glibc-common RHEL 10.2 2.39-142.el10_2
glibc-benchtests RHEL 10.2 2.39-142.el10_2
glibc-gconv-extra RHEL 10.2 2.39-142.el10_2

red hat advisories RHSA-2026:76781 RHSA-2026:60865

glibc SLES 16.0, Linux Micro Extras 6.2, Linux Micro 6.2 +1 more 2.40-160000.7.1
glibc SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 +1 more 2.38-150600.14.58.1
glibc Linux Micro 6.1 2.38-slfo.1.1_10.1
glibc Linux Micro 6.0 2.38-15.1

suse advisories SUSE-SU-2026:23934-1 SUSE-SU-2026:23957-1 SUSE-SU-2026:23929-1 SUSE-SU-2026:4250-1 SUSE-SU-2026:23738-1 SUSE-SU-2026:23830-1

glibc openSUSE Leap 16.0 2.40-160000.7.1
glibc-cross-s390x-src openSUSE Leap 16.0 2.40-160000.7.1
glibc-cross-aarch64-src openSUSE Leap 16.0 2.40-160000.7.1
glibc-cross-ppc64le-src openSUSE Leap 16.0 2.40-160000.7.1
glibc-cross-riscv64-src openSUSE Leap 16.0 2.40-160000.7.1
glibc openSUSE Tumbleweed 2.44-2.1

opensuse advisories openSUSE-SU-2026:21968-1 openSUSE-SU-2026:11787-1

glibc AlmaLinux 10 2.39-142.el10_2.alma.1
libnsl AlmaLinux 10 2.39-142.el10_2.alma.1
nss_db AlmaLinux 10 2.39-142.el10_2.alma.1
nss_hesiod AlmaLinux 10 2.39-142.el10_2.alma.1
glibc-utils AlmaLinux 10 2.39-142.el10_2.alma.1
glibc-common AlmaLinux 10 2.39-142.el10_2.alma.1
glibc-benchtests AlmaLinux 10 2.39-142.el10_2.alma.1
glibc-gconv-extra AlmaLinux 10 2.39-142.el10_2.alma.1

almalinux advisories ALSA-2026:76781

glibc Rocky Linux 10 2.39-142.el10_2

rocky linux advisories RLSA-2026:76781

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-2026-19499 updated 2026-11-07 cvss 6.8

glibc: Buffer Overflow in strfmon right-justification padding

Red Hat Enterprise Linux AppStream (v. 10) glibc-utils 2.39-142.el10_2, glibc-locale-source 2.39-142.el10_2 Red Hat Enterprise Linux BaseOS (v. 10) glibc 2.39-142.el10_2, libnsl 2.39-142.el10_2, glibc-common 2.39-142.el10_2, glibc-gconv-extra 2.39-142.el10_2, glibc-all-langpacks 2.39-142.el10_2, glibc-minimal-langpack 2.39-142.el10_2 Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) nss_db 2.39-142.el10_2, nss_hesiod 2.39-142.el10_2, glibc-benchtests 2.39-142.el10_2
fixed: vendor fix RHSA-2026:76781
Red Hat Hardened Images glibc 2.43-8.3.hum1, libnsl 2.43-8.3.hum1, nss_db 2.43-8.3.hum1, glibc32 2.43-8.3.hum1, nss_hesiod 2.43-8.3.hum1, glibc-utils 2.43-8.3.hum1, +9 more
fixed: vendor fix RHSA-2026:60865
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 9 nscd, glibc, libnsl, nss_db, nss_hesiod, glibc-utils, +6 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
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: partial
Assessed: 55 d ago (2026-09-14)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.7	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H

Affected products

The GNU C Library glibc

Classification

Weakness

CWE-122 Heap-based Buffer Overflow

References

sourceware.org /git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0017
vendor-advisory
sourceware.org /bugzilla/show_bug.cgi?id=34510
issue-tracking

Sources

CVE List CVE-2026-19499
NVD CVE-2026-19499

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.

Summary