CVE-2026-121995
Gdb: gdb: stack buffer overflow in parse_tracepoint_definition via stale rs->buf tail
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
A stack buffer overflow in the GDB client's tracepoint upload handler allows an attacker-controlled debug stub to corrupt stack memory automatically during connection setup. The overflow results from GDB reading beyond the current reply boundary into a stale prior reply in the shared packet buffer.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.29% · top 78% of all CVEs (6 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
Red Hat · Red Hat Enterprise Linux 10
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 10
All versions: affected
Red Hat · Red Hat Enterprise Linux 6
All versions: affected
Red Hat · Red Hat Enterprise Linux 7
All versions: affected
Red Hat · Red Hat Enterprise Linux 8
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 8
All versions: affected
Red Hat · Red Hat Enterprise Linux 8
All versions: affected
Red Hat · Red Hat Enterprise Linux 8
All versions: affected
Red Hat · Red Hat Enterprise Linux 9
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 9
All versions: affected
Red Hat · Red Hat Hardened Images
All versions: affected
What to do
Workaround: There is no mitigation for this vulnerability. Users should only connect GDB to trusted debug targets. --- CME Mitigation Guidance (2026-11-06) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. The highest-value action is to restrict GDB remote debugging sessions to trusted remote stubs and prevent connections to untrusted endpoints: upgrade to the corresponding fixed Red Hat builds, which apply the documented input check, closing crafted qTsP remote debug response following a longer qTfP response. Until patched, this is a concern on Linux systems running GDB remote debugging sessions connecting to remote debug targets, so Only initiate target remote debugging sessions to verified, trusted debug stubs and targets. As a compensating measure, Run SELinux in enforcing mode to confine GDB execution under mandatory access control and limit the blast radius of memory corruption. These controls limit blast radius and contain exploitation, but they do not fix the underlying stack buffer overflow defect — apply the upstream patch to fully remediate. Highest-impact CME: CME-301 SELinux (Enforcing Mode) (medium)
References (2)
- https://access.redhat.com/security/cve/CVE-2026-121995 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2565677 (opens in a new tab)issue-trackingx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-121995)Record last updated .