CVE-2026-56787
RTKLIB 2.4.3 - Off-by-One Out-of-Bounds Read in decode_ssr3 via RTCM3 SSR Message
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
RTKLIB 2.4.3 - Off-by-One Out-of-Bounds Read in decode_ssr3 via RTCM3 SSR Message
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
- Record
CVE-2026-56787- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Weakness
- CWE-193
- Updated
- 2026-11-02
EUVDEUVD-2026-39529
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
- Record
EUVD-2026-39529- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8p7j-vhgr-rcw5
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3...
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
- Record
GHSA-8p7j-vhgr-rcw5- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/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 - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Weakness
- CWE-193
- Updated
- 2026-11-02
NVD
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
- Record
CVE-2026-56787- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/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 - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-193
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-56787
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
- Record
DEBIAN-CVE-2026-56787- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-56787
RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.
- Record
UBUNTU-CVE-2026-56787- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rtklibDebian:13 |
All versions, plus listed versions 2.4.3.b34+dfsg-1 |
None known |
rtklibDebian:14 |
All versions, plus listed versions 2.4.3.b34+dfsg-1 |
None known |
rtklibUbuntu:18.04:LTS |
All versions, plus listed versions 2.4.3+dfsg1-1 |
None known |
rtklibUbuntu:20.04:LTS |
All versions, plus listed versions 2.4.3+dfsg1-12.4.3+dfsg1-2.12.4.3+dfsg1-2.1build1 |
None known |
rtklibUbuntu:22.04:LTS |
All versions, plus listed versions 2.4.3+dfsg1-2.1build12.4.3.b34+dfsg-1 |
None known |
rtklibUbuntu:24.04:LTS |
All versions, plus listed versions 2.4.3.b34+dfsg-12.4.3.b34+dfsg-1build12.4.3.b34+dfsg-1build2 |
None known |
rtklibUbuntu:25.10 |
All versions, plus listed versions 2.4.3.b34+dfsg-1build2 |
None known |
rtklibUbuntu:26.10 |
All versions, plus listed versions 2.4.3.b34+dfsg-1build3 |
None known |
rtklibUbuntu:26.04:LTS |
All versions, plus listed versions 2.4.3.b34+dfsg-1build22.4.3.b34+dfsg-1build3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-56787 is a medium vulnerability (CVSS 6.9) in Rtklib, published June 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.56%, the 47th percentile. No source names a fixed version.
References
github.com/tomojitakasu/RTKLIB/issues/798
vulncheck.com/advisories/rtklib-off-by-one-out-of-bounds-read-in-decode-ssr3-via-rtcm3-ssr-message
nvd.nist.gov/vuln/detail/CVE-2026-56787
security-tracker.debian.org/tracker/CVE-2026-56787
ubuntu.com/security/CVE-2026-56787
cve.org/CVERecord?id=CVE-2026-56787