Vulnerability · Published Oct 23, 2026 · Assigned by CPANSec
CVE-2026-113877HTTP::Headers::ActionPack versions before 0.10 for Perl allow CPU exhaustion via Accept-Language ranges matched as regular expressions
High 7.5
In plain English
A high-severity security flaw in HTTP-Headers-ActionPack. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
HTTP::Headers::ActionPack versions before 0.10 for Perl allow CPU exhaustion via Accept-Language ranges matched as regular expressions. _language_match interpolates each Accept-Language range into the pattern `/^$range\-/i` without escaping it, so regular expression syntax in the header reaches the regex engine. A 12-byte range such as `(a?|b?){26}z` backtracks for seconds, and each increment of the quantifier doubles the time. An invalid range such as `(` fails to compile. A remote attacker can exhaust CPU, or make choose_language die, in any application that passes an untrusted Accept-Language header to it.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libhttp-headers-actionpack-perl | no fix listed | DEBIAN-CVE-2026-113877 |
| Debian:13 | libhttp-headers-actionpack-perl | no fix listed | DEBIAN-CVE-2026-113877 |
| Debian:14 | libhttp-headers-actionpack-perl | 0.10-1 | DEBIAN-CVE-2026-113877 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| HTTP-Headers-ActionPack | 0 – before 0.10 |
Weakness: CWE-624 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H