How severe is CVE-2025-8277?

CVE-2025-8277 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2025-8277 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-8277?

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

Does CVE-2025-8277 have an EU (EUVD) identifier?

Yes. CVE-2025-8277 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27246.

When was CVE-2025-8277 published?

CVE-2025-8277 was published on 2025-09-09 and last updated on 2026-06-30.

CVE-2025-8277

CVE-2025-8277 is a low-severity vulnerability with a CVSS 3.x base score of 3.1. 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-401.

Key facts

Severity: Low (CVSS 3.x base score 3.1)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-27246
Weakness: CWE-401
Published: 2025-09-09
Last modified: 2026-06-30

Description

A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.

Frequently asked questions

What is CVE-2025-8277?: A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.
How severe is CVE-2025-8277?: CVE-2025-8277 has a CVSS 3.x base score of 3.1, rated low severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2025-8277 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-8277?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-8277 have an EU (EUVD) identifier?: Yes. CVE-2025-8277 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27246.
When was CVE-2025-8277 published?: CVE-2025-8277 was published on 2025-09-09 and last updated on 2026-06-30.

References

Other CWE-401 (Missing Release of Memory after Effective Lifetime) vulnerabilities

CVE-2026-46289 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: lib/scatterlist: fix length calculations in…
CVE-2022-0742 — Critical (CVSS 9.1): Memory leak in icmp6 implementation in Linux Kernel 5.13+ allows a remote attacker to DoS a host by making it go…
CVE-2024-25450 — High (CVSS 8.8): imlib2 v1.9.1 was discovered to mishandle memory allocation in the function init_imlib_fonts().
CVE-2023-33718 — High (CVSS 8.8): mp4v2 v2.1.3 was discovered to contain a memory leak via MP4File::ReadString() at mp4file_io.cpp
CVE-2021-40633 — High (CVSS 8.8): A memory leak (out-of-memory) in gif2rgb in util/gif2rgb.c in giflib 5.1.4 allows remote attackers trigger an out of…
CVE-2021-3492 — High (CVSS 8.8): Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring…

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