HTTP::Date versions before 6.08 for Perl allow CPU exhaustion via polynomial regex backtracking in parse_date

[nixpkgs-security-tracker]

Nixpkgs security tracker issue

CVE-2026-14741

HTTP::Date versions before 6.08 for Perl allow CPU exhaustion via polynomial regex backtracking in parse_date

HTTP::Date versions before 6.08 for Perl allow CPU exhaustion via polynomial regex backtracking in parse_date.

parse_date() matches the date string against a chain of alternative regexes, and str2time() delegates to it. Several of these patterns place unbounded quantifiers next to each other before a trailing \s*$ anchor. A valid date prefix followed by a long interior run of digits, letters, or whitespace and a single trailing byte that defeats the final match forces the engine to repartition the run, giving polynomial (about quadratic) backtracking. A header value of a few tens of kilobytes runs for tens of seconds of CPU.

HTTP::Date parses timestamps such as HTTP Date, Expires, and Last-Modified headers, which commonly originate from untrusted sources. Any caller that passes an untrusted date header to str2time() or parse_date() can be driven to consume unbounded CPU, a denial of service.

References

• https://github.com/libwww-perl/HTTP-Date/commit/78c20952cdfbf11e03cf1199ad70f13298a84c5c.patch (patch)
• Fix ReDoS in parse_date libwww-perl/HTTP-Date#33 (issue-tracking)
• https://metacpan.org/release/OALDERS/HTTP-Date-6.08/changes (release-notes)
• http://www.openwall.com/lists/oss-security/2026/07/17/10

Affected packages

• perlPackages.HTTPDate (pull requests)
  • 6.06@nixos-26.05
  • 6.06@nixos-unstable
• perl5Packages.HTTPDate (pull requests)
  • 6.06@nixos-26.05
  • 6.06@nixos-unstable

Next steps

• Start here if this is your first security issue: Triaging and fixing security issues
• Backports are usually needed: Backporting security fixes