Heap buffer overflow in GDB gdbserver QTDPsrc packet handler
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.
Summary
Gdb gdbserver is listed as affected in Red Hat Enterprise Linux 6, 7, 8, 9 and 10 and in Red Hat Hardened Images, with no fix listed. A heap buffer overflow in the QTDPsrc packet handler (CWE-122) occurs when a packet's declared source length does not match its actual data length, so hex2bin writes past the allocated heap buffer. An unauthenticated remote attacker can achieve native code execution in the gdbserver process.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
Description from the CNA
A heap buffer overflow in gdbserver's QTDPsrc packet handler allows an unauthenticated remote attacker to achieve native code execution in the gdbserver process. The vulnerability results from a mismatch between a packet's declared source length and the actual data length, causing hex2bin to write beyond the allocated heap buffer.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 10 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Hardened Images | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:enterprise_linux:10 | 10 | — | Red Hat |
| cpe:/o:redhat:rhel_els:6 | 6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:7 | 7 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8 | 8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9 | 9 | — | Red Hat |
| cpe:/a:redhat:hummingbird:1 | 1 | — | Red Hat |
- cpe:/a:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
- cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
- cpe:/a:redhat:hummingbird:1 Versions 1 — ·Red Hat
Remediation
The sources list no fixed version for Red Hat Enterprise Linux 6, 7, 8, 9, 10 and Red Hat Hardened Images. Red Hat lists no remediation plan available for these products.
Written with Claude Haiku 5.5 from the sources below · 2026-11-05
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Hardened Images | Affected | No fix yet |
Not affected: 3 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-11-05 Threatist record created from CVE-2026-121997
- 2026-11-05 Alias added: GHSA-jq36-9pw3-8r4v
- 2026-11-05 Affected versions changed · Red Hat
- 2026-11-05 CVSS score added · Red Hat
- 2026-11-05 CISA SSVC decision points changed
- 2026-11-05 Priority changed: MEDIUM → LOW
- 2026-11-06 CISA SSVC decision points changed
References
More Red Hat vulnerabilities
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- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-121997 · CVE Program
- CVE-2026-121997 · NVD
- FIRST EPSS
- GHSA-jq36-9pw3-8r4v · GitHub Advisory Database · CC BY 4.0
- CVE-2026-121997 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences