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Fencer Vulns
medium 5.7

CVE-2026-67550 json

re2: Out-of-bounds heap read in `exec`/`test`/`match` via attacker-influenced `lastIndex` on a non-ASCII subject → uncatchable process crash (DoS)

published 2026-07-30 3 mo ago modified 2026-10-23 16 d ago also GHSA-ff84-5f28-78qj , EUVD-2026-51297

cvss
5.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

re2 provides Node.js bindings for Google's RE2 regular expression engine. Prior to 1.25.2, re2 validates lastIndex against the UTF-8 byte length of a subject but uses it as a UTF-16 code-unit offset in exec, test, match, replace, and split, allowing an attacker-influenced lastIndex on a non-ASCII subject to trigger an out-of-bounds heap read and an uncatchable process crash, with limited heap information disclosure in some cases. This issue is fixed in 1.25.2.

Patch / fix

  • npm re2 1.25.2
  • node-re2 Debian 14 1.26.1+~cs1.7.0-1

debian advisories DEBIAN-CVE-2026-67550

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-67550 updated cvss 5.7

re2: Denial of Service via out-of-bounds read

  • Red Hat Enterprise Linux AI (RHEL AI) 3 re2
    affected: workaround, no fix available
  • Red Hat Hardened Images re2
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/uhop/node-re2/security/advisories/GHSA-ff84-5f28-78qj referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.7 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H
GitHub 3.1 5.7 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm re2
<1.25.2
1.25.2

Affected products

  • uhop node-re2

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.