CVE-2026-56788

RTKLIB 2.4.3 - Out-of-bounds Read via Negative Array Index in getcodepri

4.8 Medium

RTKLIB through 2.4.3 contains an out-of-bounds read vulnerability in getcodepri function when processing unrecognized RINEX observation codes, allowing attackers to trigger denial of service. Crafted RINEX files with unknown observation types cause negative array indexing into the codepris table, resulting in reliable crashes and potential memory disclosure of adjacent global data.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: None
User interaction: Passive

What an attacker can affect

Confidentiality: Low
Integrity: None
Availability: Low

Exploit likelihood

0.17%Up 0.1 points since Jun 26, 2026

What each source reports

CVE List Score used 4.8

RTKLIB 2.4.3 - Out-of-bounds Read via Negative Array Index in getcodepri

Record: CVE-2026-56788
CVSS 4.0: 4.8 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS 3.1: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
Weakness: CWE-125
Updated: 2026-11-02

EUVDEUVD-2026-39530 4.8

Record: EUVD-2026-39530
CVSS 4.0: 4.8 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-m65p-fp8q-q43h 4.8

RTKLIB through 2.4.3 contains an out-of-bounds read vulnerability in getcodepri function when...

Record: GHSA-m65p-fp8q-q43h
CVSS 4.0: 4.8 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/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: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
Weakness: CWE-125
Updated: 2026-11-02

NVD 4.8

Record: CVE-2026-56788
CVSS 4.0: 4.8 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/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: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
CVSS 3.1: 7.1 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Weakness: CWE-125
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-56788 7.1

Record: DEBIAN-CVE-2026-56788
CVSS 3.1: 7.1 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-56788 4.8

Record: UBUNTU-CVE-2026-56788
CVSS 4.0: 4.8 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS 3.1: 7.1 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
CVSS 3.1: 4.4 MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`rtklib` Debian:13	All versions, plus listed versions 2.4.3.b34+dfsg-1	None known
`rtklib` Debian:14	All versions, plus listed versions 2.4.3.b34+dfsg-1	None known
`rtklib` Ubuntu:18.04:LTS	All versions, plus listed versions 2.4.3+dfsg1-1	None known
`rtklib` Ubuntu: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
`rtklib` Ubuntu:22.04:LTS	All versions, plus listed versions 2.4.3+dfsg1-2.1build12.4.3.b34+dfsg-1	None known
`rtklib` Ubuntu: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
`rtklib` Ubuntu:25.10	All versions, plus listed versions 2.4.3.b34+dfsg-1build2	None known
`rtklib` Ubuntu:26.10	All versions, plus listed versions 2.4.3.b34+dfsg-1build3	None known
`rtklib` Ubuntu:26.04:LTS	All versions, plus listed versions 2.4.3.b34+dfsg-1build22.4.3.b34+dfsg-1build3	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-56788 is a medium vulnerability (CVSS 4.8) in Rtklib, published June 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. No source names a fixed version.