CVE-2026-56789: RTKLIB through 2.4.3 contains a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c

Q: How do I fix CVE-2026-56789?

rtklib: upgrade to newer than 2.4.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-56789 being exploited?

CVE-2026-56789 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-56789 affect?

CVE-2026-56789 affects rtklib. Severity is medium (CVSS 6.5). RTKLIB through 2.4.3 contains a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c that allows attackers to trigger memory corruption by failing to clamp satellite count values from RINEX epoch headers. Attackers

Q: How urgent is CVE-2026-56789?

Priority 37/100. Public exploit reference

Routine

MEDIUM 6.5UPGRADE

CVE-2026-56789 is a medium-severity flaw (CVSS 6.5) affecting rtklib. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

RTKLIB through 2.4.3 contains a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c that allows attackers to trigger memory corruption by failing to clamp satellite count values from RINEX epoch headers. Attackers can craft malicious RINEX files declaring more than 64 satellites per epoch to cause heap buffer overflow writes and out-of-bounds stack reads, crashing RTKLIB-based applications including rnx2rtkp and RTKPOST.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-122
Published	2026-06-25
Last modified	2026-10-25

Publisher (CNA): VulnCheck · Vendor: rtklib

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-25 19:16 UTCPublished CVE record published
2026-10-25 22:10 UTCUpdated Record last modified

rtklib rtklib UPGRADE

Affected: <= 2.4.3

Fixed in: newer than 2.4.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy rtklib || rpm -q rtklib || rtklib --version

2. UPGRADE to newer than 2.4.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade rtklib

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade rtklib

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-56789?

rtklib: upgrade to newer than 2.4.3. Exact commands for each OS are on this page.

Is CVE-2026-56789 being exploited?

CVE-2026-56789 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-56789 affect?

CVE-2026-56789 affects rtklib. Severity is medium (CVSS 6.5). RTKLIB through 2.4.3 contains a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c that allows attackers to trigger memory corruption by failing to clamp satellite count values from RINEX epoch headers. Attackers

How urgent is CVE-2026-56789?

Priority 37/100. Public exploit reference

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References

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