Vulnerability · Published Feb 20, 2026 · Assigned by VulDB

CVE-2026-2858wren-lang wren Source File wren_compiler.c peekChar out-of-bounds

Low 3.3

In plain English

A low-severity out-of-bounds read in wren from wren-lang. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities).

Severity (CVSS 3.1)3.3Low

Exploit odds (30 days)0.1%top 96.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

A vulnerability was identified in wren-lang wren up to 0.4.0. This affects the function peekChar of the file src/vm/wren_compiler.c of the component Source File Parser. Such manipulation leads to out-of-bounds read. The attack needs to be performed locally. The exploit is publicly available and might be used. The project was informed of the problem early through an issue report but has not responded yet.

Affected products (as reported)

Vendor	Product	Versions
wren-lang	wren	0.10.20.30.4.0

Weakness: CWE-125, CWE-119 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R

References

VDB-347097 | wren-lang wren Source File wren_compiler.c peekChar out-of-bounds vdb-entry, technical-description
VDB-347097 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
Submit #754489 | wren-lang wren main-branch Heap-based Buffer Overflow third-party-advisory
https://github.com/wren-lang/wren/issues/1217 issue-tracking
https://github.com/oneafter/0122/blob/main/i1217/repro exploit
https://github.com/wren-lang/wren/ product