GNU Gatekeeper before 5.16 Out-of-Bounds Read in H.460.24 RTCP Probe Handler
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 5.16
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 5.16.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Data gap: No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity6.3/10CVSS 6.3
- No patch0/5No signal
What would change the score
- Would score about 68 if added to CISA KEV
- Would score about 63 if CISA's SSVC rates exploitation active
- Would score about 28 if advisories confirm default setups are exposed
CVE-2026-121626 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.3 (medium) and affects gnugk; fixed in 5.16.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- 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? →
- 23/100 · provisional
- Fix
- Fixed in 5.16
- 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
Summary
GNU Gatekeeper (gnugk), an H.323 gatekeeper used for managing VoIP and video calls, is affected by this flaw in its H.460.24 media probing feature. A remote attacker can send a specially crafted short packet to the media port that causes the software to read memory beyond its allocated bounds, which may crash the gatekeeper.
Read the original description
GNU Gatekeeper (gnugk) before 5.16 contains an out-of-bounds read vulnerability in H46024Socket::ReceivedProbePacket() that allows remote attackers to cause a heap over-read by sending short probe packets. Attackers can send a short application-defined RTCP packet to the media port during H.460.24 probing to read past the heap allocation and possibly crash the gatekeeper.
What to do
Upgrade to a fixed version: 5.16.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- willamowius gnugk
fixed in 5.16
Evidence 5
- Patch
- Repository
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-121626
Is CVE-2026-121626 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
Which versions are affected by CVE-2026-121626?
gnugk: before 5.16.Source: cve.now feed data
How do I fix CVE-2026-121626?
Upgrade to a fixed version: 5.16.Source: cve.now feed data