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Fencer Vulns
high 7.5

CVE-2025-55763 json

Buffer Overflow in the URI parser of CivetWeb 1.14 through 1.16 (latest) allows a remote attacker to achieve remote code execution via a cr…

published 2025-08-29 14 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-26228

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

Buffer Overflow in the URI parser of CivetWeb 1.14 through 1.16 (latest) allows a remote attacker to achieve remote code execution via a crafted HTTP request. This vulnerability is triggered during request processing and may allow an attacker to corrupt heap memory, potentially leading to denial of service or arbitrary code execution.

Patch / fix

  • civetweb Debian 13 1.16+dfsg-2+deb13u1
  • civetweb Debian 14 1.16+dfsg-3

debian advisories DEBIAN-CVE-2025-55763

  • civetweb Ubuntu 24.04 LTS 1.16+dfsg-1ubuntu0.1
  • civetweb Ubuntu 26.10, Ubuntu 26.04 LTS 1.16+dfsg-3
  • civetweb Ubuntu Pro 22.04 LTS 1.15+dfsg-3ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2025-55763

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • civetweb openSUSE Tumbleweed 1.6+git1776611085.588860e3-1.1

opensuse advisories openSUSE-SU-2026:10818-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-55763 updated cvss 5.3

civetweb: CivetWeb buffer overflow

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
14 mo ago

Exploit prediction

1.20% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/krispybyte/CVE-2025-55763 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.