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CVE-2026-121626

GNU Gatekeeper before 5.16 Out-of-Bounds Read in H.460.24 RTCP Probe Handler

CVSS score

6.3

EPSS probability

—

Risk score

0.6

Published

3 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

CVE-2026-121626: GNU Gatekeeper Out-of-Bounds Read in H.460.24 RTCP Probe Handler

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

GNU Gatekeeper (gnugk) before version 5.16 contains an out-of-bounds read vulnerability in the H.460.24 RTCP probe handler. Remote attackers can send short probe packets to cause a heap over-read and potentially crash the gatekeeper service.

Why does it matter?

This vulnerability allows remote attackers to target network services without authentication and induce denial-of-service conditions. Applying available patches and updates is crucial to secure affected environments.

What should be done?

  • Review the provided patch references
  • Follow vendor advisories to apply updates
  • Upgrade affected components to secure releases
Chain of evidence and sources2 verified claims

GNU Gatekeeper 5.16 öncesi sürümler H.460.24 RTCP sınama işleyicisinde bir sınır dışı okuma açığı barındırır.

S0 · daybreach-canonicalS1 · cvelist

Saldırganlar kısa RTCP paketleri göndererek yığın aşırı okumasına ve uygulamanın çökmesine yol açabilir.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

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.

CVSS vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CWE: CWE-125

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-121626 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1willamowiusgnugk View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
6.3CVSS V4_0MEDIUMCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NCVE CNA
6.3CVSS V40MEDIUMCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD
3.7CVSS V3_1LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LCVE CNA
3.7CVSS V31LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

cvelist

Patch Commit

Open source
reference

Patch Commit

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-121626 is associated with the following CWEs:

CWE-125: Out-of-bounds Read

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-121626 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

Patch Commitpatchgnugk v5_16 Release Notesvendor-advisoryhttps://github.com/willamowius/gnugk/blob/v5_15/GkClient.cxx#L963-L990vendor-advisoryhttps://github.com/willamowius/gnugkvendor-advisoryVulnCheck Advisory: GNU Gatekeeper before 5.16 Out-of-Bounds Read in H.460.24 RTCP Probe Handlervendor-advisory

CVSS Vector Radar Chart

6.3 / 10
Attack VectorNetworkComplexityHighPrivilegesNoneUser Interact.NoneConfidentialityHighIntegrityNoneAvailabilityLow

Vulnerability Scoring Details

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)High
Integrity (Bütünlük)None
Availability (Erişilebilirlik)Low

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

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Weakness Type (CWE & CAPEC)

CWE-125

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CVE-2026-121626 · GNU Gatekeeper before 5.16 Out-of-Bounds…