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Fencer Intel
high 8.8

CVE-2026-121994 json

Gdb: gdb: stack buffer overflow in fetch_register_using_p via unchecked p-reply length

published 4d ago modified 3d ago also EUVD-2026-117571

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

A stack buffer overflow in the GDB client's remote protocol handler allows an attacker-controlled debug target to execute arbitrary code in the GDB process. The vulnerability exists in fetch_register_using_p, which decodes a stub's register reply into an alloca-sized buffer without bounding writes by the register width.

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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-2026-121994 updated cvss 8.8

gdb: gdb: stack buffer overflow in fetch_register_using_p via unchecked p-reply length

  • Red Hat Enterprise Linux 6 gdb, gdb-gdbserver, gdb 17.2-4.el10_3 Red Hat Enterprise Linux 7 gdb-gdbserver, gdb 17.2-4.el10_3 Red Hat Enterprise Linux 8 gdb, gdb-headless, gdb-gdbserver, gdb 17.2-4.el10_3, gcc-toolset-14-gdb 14.2-3.el8_10, gcc-toolset-15-gdb 16.3-1.el8_10 Red Hat Enterprise Linux 9 gdb, gdb-minimal, gdb-headless, gdb-gdbserver, gdb 17.2-4.el10_3 Red Hat Enterprise Linux 10 gdb 17.2-4.el10_3 Red Hat Hardened Images gdb 17.2-4.el10_3
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 8 crash 8.0.6-1.el10 Red Hat Enterprise Linux 9 crash 8.0.6-1.el10 Red Hat Enterprise Linux 10 crash 8.0.6-1.el10
    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
5d ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Hardened Images

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow

References

Sources

Fencer Intel 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.