CVE-2026-121997
Gdb: gdbserver: heap buffer overflow in cmd_qtdpsrc via qtdpsrc declared/actual length mismatch
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Gdb: gdbserver: heap buffer overflow in cmd_qtdpsrc via qtdpsrc declared/actual length mismatch
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.
- Record
CVE-2026-121997- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-06
EUVDEUVD-2026-117574
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.
- Record
EUVD-2026-117574- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-06
GitHub AdvisoriesGHSA-jq36-9pw3-8r4v
A heap buffer overflow in gdbserver's QTDPsrc packet handler allows an unauthenticated remote...
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.
- Record
GHSA-jq36-9pw3-8r4v- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-05
NVD
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.
- Record
CVE-2026-121997- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-06
OSVDEBIAN-CVE-2026-121997
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.
- Record
DEBIAN-CVE-2026-121997- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-06
OSVUBUNTU-CVE-2026-121997
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.
- Record
UBUNTU-CVE-2026-121997- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-07
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
gdbDebian:12 |
All versions, plus listed versions 13.1-313.2-113.2-1+hurd.315.1-115.2-1 Show 36 moreShow less15.2-2~exp116.0.90.20250111-1~exp116.0.90.20250111-1~exp216.1-116.1-216.1-2+hurd.116.2-116.2-216.2-316.2-416.2-516.2-616.2-716.2-816.3-116.3-216.3-316.3-416.3-4~bpo13+116.3-4~bpo13+216.3-516.3-5~bpo13+117.0.50.20250905-1~exp117.0.90-1~exp117.0.90-1~exp217.1-117.1-1~bpo13+117.1-217.1-317.1-417.2-117.2-1~bpo13+118.1-118.1-218.1-318.1-3~bpo13+1 |
None known |
gdbDebian:13 |
All versions, plus listed versions 16.3-116.3-216.3-316.3-416.3-4~bpo13+1 Show 17 moreShow less16.3-4~bpo13+216.3-516.3-5~bpo13+117.0.50.20250905-1~exp117.0.90-1~exp117.0.90-1~exp217.1-117.1-1~bpo13+117.1-217.1-317.1-417.2-117.2-1~bpo13+118.1-118.1-218.1-318.1-3~bpo13+1 |
None known |
gdbDebian:14 |
All versions, plus listed versions 16.3-116.3-216.3-316.3-416.3-4~bpo13+1 Show 17 moreShow less16.3-4~bpo13+216.3-516.3-5~bpo13+117.0.50.20250905-1~exp117.0.90-1~exp117.0.90-1~exp217.1-117.1-1~bpo13+117.1-217.1-317.1-417.2-117.2-1~bpo13+118.1-118.1-218.1-318.1-3~bpo13+1 |
None known |
gdbUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 7.10-1ubuntu27.10-1ubuntu37.10.1-0ubuntu17.10.90.20160215-0ubuntu27.10.90.20160220-0ubuntu1 Show 4 moreShow less7.11-0ubuntu17.11.1-0ubuntu1~16.047.11.1-0ubuntu1~16.57.11.1-0ubuntu1~16.5+esm1 |
None known |
gdbUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 8.0.1-0ubuntu18.0.1-0ubuntu28.0.1-0ubuntu38.1-0ubuntu18.1-0ubuntu2 Show 5 moreShow less8.1-0ubuntu38.1-0ubuntu3.18.1-0ubuntu3.28.1.1-0ubuntu18.1.1-0ubuntu1+esm1 |
None known |
gdbUbuntu:20.04:LTS |
All versions, plus listed versions 8.3-0ubuntu19.0.50.20191019-0ubuntu19.0.50.20191119-0ubuntu19.0.90.20191216-0ubuntu19.0.90.20200105-0ubuntu1 Show 5 moreShow less9.0.90.20200117-0ubuntu19.1-0ubuntu19.2-0ubuntu1~20.049.2-0ubuntu1~20.04.19.2-0ubuntu1~20.04.2 |
None known |
gdbUbuntu:22.04:LTS |
All versions, plus listed versions 11.1-0ubuntu211.1-0ubuntu311.2-0ubuntu112.0.50.20220217-0ubuntu112.0.90-0ubuntu112.1-0ubuntu1~22.0412.1-0ubuntu1~22.04.2 |
None known |
gdbUbuntu:24.04:LTS |
All versions, plus listed versions 14.0.50.20230907-0ubuntu114.1-0ubuntu114.1-0ubuntu215.0.50.20240219-0ubuntu115.0.50.20240320-0ubuntu115.0.50.20240403-0ubuntu115.1-1ubuntu1~24.04.1 |
None known |
gdbUbuntu:26.10 |
All versions, plus listed versions 17.1-2ubuntu117.2-1ubuntu1 |
None known |
gdbUbuntu:26.04:LTS |
All versions, plus listed versions 16.3-1ubuntu216.3-5ubuntu117.1-1ubuntu117.1-1ubuntu217.1-2ubuntu1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | CVE List, EUVD, OSV | |
| affected, aliases, references | CVE List, EUVD, NVD, OSV | |
| aliases, references | GitHub Advisories | |
| aliases, published | EUVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-121997 is a high vulnerability (CVSS 8.1) in Red Hat Enterprise Linux 10, published November 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.71%, the 53rd percentile. No source names a fixed version.