How severe is CVE-2026-56787?

CVE-2026-56787 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.

Is CVE-2026-56787 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-56787?

CVE-2026-56787 affects Rtklib. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-56787?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-56787 have an EU (EUVD) identifier?

Yes. CVE-2026-56787 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39529.

When was CVE-2026-56787 published?

CVE-2026-56787 was published on 2026-06-25 and last updated on 2026-06-26.

CVE-2026-56787

CVE-2026-56787 is a medium-severity vulnerability in Rtklib with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-193.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 6.9
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39529
Weakness: CWE-193
Affected product: Rtklib
Published: 2026-06-25
Last modified: 2026-06-26

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-56787?: CVE-2026-56787 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2026-56787 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-56787?: CVE-2026-56787 affects Rtklib. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-56787?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-56787 have an EU (EUVD) identifier?: Yes. CVE-2026-56787 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39529.
When was CVE-2026-56787 published?: CVE-2026-56787 was published on 2026-06-25 and last updated on 2026-06-26.

References

Affected products (1)

cpe:2.3:a:rtklib:rtklib:*:*:*:*:*:*:*:*

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