CVE-2026-55777: GoAccess: Out-of-bounds heap read in parse_ios() via crafted User-Agent leads to remote crash/DoS

Severity: medium (CVSS 5.3 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-30 · updated 2026-10-23
Weakness: CWE-125

Description

GoAccess is a real-time web log analyzer and interactive viewer that runs in a terminal in *nix systems or through the browser. Prior to 1.11, the parse_ios() function uses an attacker-controlled keyword-to-OS offset as both the source offset and copy length for memmove, allowing a crafted User-Agent in a processed access log to read up to approximately 4 KB beyond the heap allocation and conditionally crash GoAccess. This issue is fixed in version 1.11.

Affected products

allinurl goaccess: before 1.11

References

https://github.com/allinurl/goaccess/commit/ba813ed97d998dbdcb8d87e178799a4bb2da9e81
https://github.com/allinurl/goaccess/security/advisories/GHSA-5phr-qpgf-hgrg
https://github.com/allinurl/goaccess/security/advisories/GHSA-5phr-qpgf-hgrg

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