Out-of-bounds Read in Pevans Socket
CVE-2026-12087
Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the byte length carried over from the preceding multiaddr argument instead. Both addresses occupy a 4-byte field, so a valid multiaddr lets a source of any length pass the check, and the source is then copied into the 4-byte imr_sourceaddr field with a fixed-size copy. A source shorter than 4 bytes is not rejected, and the copy reads up to 3 bytes past the end of its buffer. Calling pack_ip_mreq_source() with a source value shorter than 4 bytes copies adjacent heap memory into the returned packed structure.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (29.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Pevans Socket — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
Frequently asked questions
- What is CVE-2026-12087?
- CVE-2026-12087 is a critical-severity vulnerability in Pevans Socket, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-06-15.
- How severe is CVE-2026-12087?
- Critical severity. CVSS v3 base score is 9.1 out of 10.
- Is CVE-2026-12087 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.