CVE-2026-121625

GNU Gatekeeper before 5.16 Out-of-Bounds Read via RTCP SDES Parsing

CVSS score

6.3

EPSS probability

—

Risk score

0.6

Published

3 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

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Vulnerability description

DayBreach AI Explanation

Verified against sources

GNU Gatekeeper Before 5.16 Out-of-Bounds Read Vulnerability

Sources read

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

GNU Gatekeeper (gnugk) before 5.16 contains an out-of-bounds read vulnerability in ParseRTCP() within ProxyChannel.cxx allowing remote heap memory reading.

Why does it matter?

Remote attackers can trigger a denial of service by sending crafted RTCP SDES items to the media proxy port.

What should be done?

Upgrade the software to version 5.16 or later
Follow vendor advisories and patch recommendations
Apply the corresponding patch commit

Chain of evidence and sources3 verified claims

GNU Gatekeeper 5.16 öncesi sürümlerde ProxyChannel.cxx içindeki ParseRTCP işlevinde sınır dışı okuma zafiyeti mevcuttur.

S0 · daybreach-canonical S1 · cvelist

Saldırganlar NUL baytı olmayan RTCP SDES öğeleri göndererek gatekeeper uygulamasını çökletebilir.

S0 · daybreach-canonical S1 · cvelist

Zafiyetin giderilmesi için doğrulanmış yama veya düzeltilmiş sürüm kanıtı mevcuttur.

S0 · daybreach-canonical

Show the technical text from the sources

GNU Gatekeeper (gnugk) before 5.16 contains an out-of-bounds read vulnerability in ParseRTCP() in ProxyChannel.cxx that allows remote RTP peers to read heap memory past received packets. Attackers can send RTCP SDES items lacking a NUL byte to the media proxy port during proxied H.323 calls with EnableRTCPStats enabled, crashing 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-2026-121625 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	willamowius	gnugk	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.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
6.3	CVSS V4_0	MEDIUM	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	CVE CNA
6.3	CVSS V40	MEDIUM	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/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:X	NVD
3.7	CVSS V3_1	LOW	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L	CVE CNA
3.7	CVSS V31	LOW	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L	NVD

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-2026-121625 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-2026-121625 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekmiyor

Official Sources and Advisories

Patch Commitpatch gnugk v5_16 Release Notesvendor-advisory https://github.com/willamowius/gnugk/blob/v5_15/ProxyChannel.cxx#L14867-L14895vendor-advisory https://github.com/willamowius/gnugkvendor-advisory VulnCheck Advisory: GNU Gatekeeper before 5.16 Out-of-Bounds Read via RTCP SDES Parsingvendor-advisory

CVSS Vector Radar Chart

6.3 / 10

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.

Follow the vendor

willamowius

Weakness Type (CWE & CAPEC)

CWE-125

Similar Vulnerabilities

6.3

CVE-2026-121626GNU Gatekeeper before 5.16 Out-of-Bounds Read in H.460.24 RTCP Probe Handler

Vendorwillamowius Productgnugk

Patch verified3 h ago

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