NULL pointer dereference in Skvadrik Re2c
CVE-2026-2903
A flaw has been found in skvadrik re2c up to 4.4. Impacted is the function check_and_merge_special_rules of the file src/parse/ast.cc. This manipulation causes null pointer dereference. The attack can only be executed locally. The exploit has been published and may be used. Patch name: febeb977936f9519a25d9fbd10ff8256358cdb97. It is suggested to install a patch to address this issue.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.002 (5.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Skvadrik Re2c — versions 4.0, 4.1, 4.2
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, vdb-entry)
- vuldb.com/ (signature, permissions-required)
- vuldb.com/ (third-party-advisory)
- github.com/skvadrik/re2c/issues/571 (issue-tracking)
- github.com/skvadrik/re2c/issues/571 (issue-tracking)
- github.com/oneafter/0202/blob/main/re/repro (exploit)
- github.com/skvadrik/re2c/commit/febeb977936f9519a25d9fbd10ff8256358cdb97 (patch)
- github.com/skvadrik/re2c/ (product)
Frequently asked questions
- What is CVE-2026-2903?
- CVE-2026-2903 is a low-severity vulnerability in Skvadrik Re2c, classified under Improper Resource Shutdown or Release. CVSS score: 3.3/10. Published 2026-02-22.
- How severe is CVE-2026-2903?
- Low severity. CVSS v3 base score is 3.3 out of 10.