Process crash via invalid UTF backward scan
Published Sep 11, 2026 · Updated Sep 11, 2026
Out-of-bounds reads in PCRE2 10.34 through 10.47 allow remote attackers to crash a process via a crafted invalid UTF subject. In pcre2_match(), the OP_VREVERSE and extended-grapheme scans bound backward traversal at start_subject instead of check_subject, letting BACKCHAR cross before the validated UTF region and subject buffer. Exploitation requires PCRE2_UTF, PCRE2_MATCH_INVALID_UTF, attacker-influenced invalid input, and an affected lookbehind or \X path; data disclosure has not been demonstrated.
Summary
What happened
Out-of-bounds reads in PCRE2 10.34 through 10.47 allow remote attackers to crash a process via a crafted invalid UTF subject. In pcre2_match(), the OP_VREVERSE and extended-grapheme scans bound backward traversal at start_subject instead of check_subject, letting BACKCHAR cross before the validated UTF region and subject buffer. Exploitation requires PCRE2_UTF, PCRE2_MATCH_INVALID_UTF, attacker-influenced invalid input, and an affected lookbehind or \X path; data disclosure has not been demonstrated.
The record
- CVE
- CVE-2026-89160
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- PCRE2 Project
- Product
- PCRE2
- Classifications
- CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.34 <10.48
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Upstream AddressSanitizer proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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