Gdb: gdb: stack buffer overflow in parse_tsv_definition via stale rs->buf tail
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Not reported
Do first: Workaround: Until a fixed build is installed, avoid connecting GDB to remote debug targets that are not fully trusted. Limiting remote debugging to trusted stubs is the only mitigation the checked facts support. No vendor-published workaround is given.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 43/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
The GNU debugger (GDB) has a stack buffer overflow that a malicious remote debug target can trigger while GDB parses its replies, which can crash GDB or potentially let the target run arbitrary code in the GDB client process with the privileges of the user running GDB. The page has no CVSS vector, so it does not state how an attacker reaches the bug.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
A flaw was found in the GNU debugger (GDB). When GDB connects to a remote debug target, a malicious target can cause GDB to overflow a buffer on the stack while parsing the target's replies. This can crash GDB or potentially allow the target to execute arbitrary code in the GDB client process with the privileges of the user running GDB.
cve.now Index
- Exploitation0/40No signal
- Exposure20/25No login or user action needed, CISA rates it automatable · Unknown: Advisories don't say whether default setups are affected
- Reach10/20Shipped in major Linux distributions
- Severity7.5/10CVSS 7.5
- No patch5/5No patch listed yet
What would change the score
- Would score about 88 if added to CISA KEV
- Would score about 83 if CISA's SSVC rates exploitation active
- Would score about 48 if advisories confirm default setups are exposed
What to do
Workaround: Until a fixed build is installed, avoid connecting GDB to remote debug targets that are not fully trusted. Limiting remote debugging to trusted stubs is the only mitigation the checked facts support. No vendor-published workaround is given.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- crash
Version range not reported
- gdb
Version range not reported
- gdb
Version range not reported
- gdb
Version range not reported
- crash
Version range not reported
- gcc-toolset-14-gdb
Version range not reported
- gcc-toolset-15-gdb
Version range not reported
- gdb
Version range not reported
Show all 11 packagesShow fewer packages
- crash
Version range not reported
- gdb
Version range not reported
- gdb
Version range not reported
Evidence 2
- Report
- Link
Corrections
None so far.
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Questions about CVE-2026-123151
Is CVE-2026-123151 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
When GDB connects to a remote debug target, a malicious target can overflow a buffer on the stack in parse_tsv_definition. The overflow fires during the connection handshake when the remote stub reports tracing support. The result can be a GDB crash, or possibly arbitrary code execution in the GDB client process with the privileges of the user running GDB.Source: access.redhat.com
Am I affected, and how do I check?
The checked facts list Red Hat Enterprise Linux 6, 7, 8, 9 and 10, and Red Hat Hardened Images, but give no version ranges. The bug requires a GDB session connected to a remote debug target whose stub reports tracing support during the handshake. To check a system, run gdb --version to see the installed GDB build and compare it with the package version in the Red Hat advisory.Source: access.redhat.com
How do I fix CVE-2026-123151?
Update the gdb package to the fixed build named in the Red Hat advisory for the relevant product. The checked facts do not name a fixed version, so take the target version from the advisory rather than assuming one.Source: access.redhat.com
What if there's no patch?
Until a fixed build is installed, avoid connecting GDB to remote debug targets that are not fully trusted. Limiting remote debugging to trusted stubs is the only mitigation the checked facts support. No vendor-published workaround is given.Source: access.redhat.com