CVE-2026-77781

HIGHCVSS 7.5/10EPSS 0.24%

Last modified

CVE-2026-77781 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Tie::Hash::Regex versions before 2.0.0 for Perl will throw an exception on unparseable lookup keys. The FETCH, EXISTS and DELETE methods throw an exception when on malformed regular expressions. Each method falls back to a regex match when the key is not already stored in the hash, compiling the caller's key with a bare qr// and no eval guard. A key that is not a valid regular expression pattern, such as a single unmatched bracket, dies. An application that looks up externally supplied strings in a tied hash will die on an invalid key.. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

Description

Tie::Hash::Regex versions before 2.0.0 for Perl will throw an exception on unparseable lookup keys. The FETCH, EXISTS and DELETE methods throw an exception when on malformed regular expressions. Each method falls back to a regex match when the key is not already stored in the hash, compiling the caller's key with a bare qr// and no eval guard. A key that is not a valid regular expression pattern, such as a single unmatched bracket, dies. An application that looks up externally supplied strings in a tied hash will die on an invalid key.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.24%

14.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
< 2.0.0

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-77781?
Tie::Hash::Regex versions before 2.0.0 for Perl will throw an exception on unparseable lookup keys. The FETCH, EXISTS and DELETE methods throw an exception when on malformed regular expressions. Each method falls back to a regex match when the key is not already stored in the hash, compiling the caller's key with a bare qr// and no eval guard. A key that is not a valid regular expression pattern, such as a single unmatched bracket, dies. An application that looks up externally supplied strings in a tied hash will die on an invalid key.
How severe is CVE-2026-77781?
CVE-2026-77781 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.
How do I fix CVE-2026-77781?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST