CVE-2026-5188 json
Integer underflow in X.509 SAN parsing in wolfSSL
published 2026-04-10 7 mo ago modified 2026-07-18 3 mo ago also EUVD-2026-21290 , GHSA-9qgc-pcpx-g38q , JLSEC-2026-715
- cvss
- 8.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 3%
- public exploits
- 0
- none known
Summary
An integer underflow issue exists in wolfSSL when parsing the Subject Alternative Name (SAN) extension of X.509 certificates. A malformed certificate can specify an entry length larger than the enclosing sequence, causing the internal length counter to wrap during parsing. This results in incorrect handling of certificate data. The issue is limited to configurations using the original ASN.1 parsing implementation which is off by default.
Patch / fix
- julia wolfSSL_jll 5.9.2+0
- wolfssl Alpine 3.24, Alpine 3.23 5.9.1-r0
alpine advisories ALPINE-CVE-2026-5188
Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- github.com/wolfSSL/wolfssl#10024 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 2.3 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N |
| CNA | 4.0 | 2.3 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H |
| OSV | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| julia | wolfSSL_jll | <5.9.2+0 |
5.9.2+0 |
Affected products
- wolfSSL wolfSSL
Classification
- Weakness
-
- CWE-191 Integer Underflow (Wrap or Wraparound)
References
-
github.com
/wolfSSL/wolfssl/pull/10024
issue-tracking, patch, web
-
github.com
/advisories/GHSA-9qgc-pcpx-g38q
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-5188
web
Sources
- CVE List CVE-2026-5188
- NVD CVE-2026-5188
- OSV JLSEC-2026-715
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.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.