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TI-2026-40950 Aliases CVE-2026-56786GHSA-5cx9-6hw2-hchv

RTKLIB 2.4.3 - Out-of-bounds Write in decode_type1033 via Crafted RTCM3 Message

Priority HIGH 81CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

RTKLIB through 2.4.3 contains an out-of-bounds write vulnerability in decode_type1033 function that fails to clamp length counters to destination buffer size, allowing up to 191-byte overflow into fixed 64-byte descriptor fields. An attacker controlling an NTRIP or serial RTCM3 correction stream can craft a valid CRC-bearing type-1033 message to corrupt adjacent rtcm_t object members, potentially achieving arbitrary code execution or denial of service.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00711 53rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA and NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
tomojitakasuRTKLIBup to 2.4.3—No fix listedCNA
  • RTKLIB Vendortomojitakasu Affected up to 2.4.3 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:rtklib:rtklib:*:*:*:*:*:*:*:*up to 2.4.3Vulnerabletomojitakasu
  • cpe:2.3:a:rtklib:rtklib:*:*:*:*:*:*:*:* Versions up to 2.4.3 Vulnerable ·tomojitakasu

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56786
  2. 2026-10-03 Alias added: GHSA-5cx9-6hw2-hchv

References

Exploit 1

  • TI-2026-40951 RTKLIB 2.4.3 - Off-by-One Out-of-Bounds Read in decode_ssr3 via RTCM3 SSR Message CVSS 4.0MEDIUM 6.9
  • TI-2026-40953 RTKLIB 2.4.3 - Heap Buffer Overflow and Stack Read via Oversized RINEX Epoch Satellite Count CVSS 4.0HIGH 7.1
  • TI-2026-40952 RTKLIB 2.4.3 - Out-of-bounds Read via Negative Array Index in getcodepri CVSS 4.0MEDIUM 4.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences