CVE-2026-77299 (GCVE-0-2026-77299)

Vulnerability from cvelistv5 – Published: 2026-11-06 01:28 – Updated: 2026-11-06 17:43
VLAI
Title
Regexp2: Unbounded memory amplification via large `{m}` quantifier on a zero-width subexpression
Summary
Regexp2 is a feature-rich RegExp engine for Go. Prior to version 2.3.0, when regexp2 compiles and matches a pattern containing a large fixed-count quantifier applied to a zero-width subexpression — e.g. (?:){50000000} — the match engine executes the empty loop body m-1 times, pushing two integers onto the backtracking stack on every iteration. Because the parser accepts any repetition count up to math.MaxInt32 and the backtracking stack grows without bound, a pattern of fewer than 20 bytes matched against an empty input can force multi-gigabyte allocation and OOM-kill the process. MatchTimeout does not fully mitigate this because the memory is allocated faster than the 100 ms timeout clock can fire. This issue has been patched in version 2.3.0.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-06 17:43 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 8074 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
dlclark regexp2 Affected: < 2.3.0
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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