Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Affects Red HatSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade Red Hat regexp2 to 2.3.0 soon.
Data as of 13 Nov 2026, 14:35 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 2.3.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade regexp2 and github.com/dlclark/regexp2 to 2.3.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| dlclarkregexp2 | Affected
| Fixed in
|
Gogithub.com/dlclark/regexp2pkg:golang/github.com/dlclark/regexp2Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in regexp2 version 2.3.0 and corresponding Red Hat builds (hugo-0.169.0-0.2.hum1). Users should upgrade to these fixed versions to fully remediate the issue. Until patched, mitigate by restricting regular expression compilation to trusted administrative inputs only, validating and rejecting patterns with large repetition quantifiers or zero-width repetitions, and enforcing per-process memory limits (e.g., RLIMIT_AS) and container resource limits (cgroups v2) to contain memory consumption. These mitigations reduce risk but do not fix the underlying vulnerability.
Description
A vulnerability in the regexp2 library used by Red Hat Hardened Images allows remote attackers to cause a denial of service by submitting crafted regular expressions with large repetition quantifiers on empty subexpressions. This triggers unbounded memory allocation in the matching engine's backtracking stack, rapidly exhausting system resources and crashing the application. The issue affects Go applications that compile or evaluate untrusted user-supplied regular expressions using regexp2. Mitigation options are limited, with the primary fix being an upgrade to regexp2 version 2.3.0 or corresponding Red Hat builds that enforce backtracking limits. Until patched, restricting regular expression compilation to trusted inputs and applying resource limits can reduce risk.
References
- access.redhat.com/errata/RHSA-2026:99590 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-77299 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- images.redhat.com (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_99590.json (opens in a new tab)