Potential non-constant time compiled code with Clang LLVM

published 2025-12-11 10 mo ago modified 2026-10-14 25 d ago also EUVD-2025-202756 , GHSA-7582-g6xx-939j , JLSEC-2026-688

cvss: 1.0; version 4.0, CNA
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

Multiple constant-time implementations in wolfSSL before version 5.8.4 may be transformed into non-constant-time binary by LLVM optimizations, which can potentially result in observable timing discrepancies and lead to information disclosure through timing side-channel attacks.

Patch / fix

fixed in 2 links 1

julia wolfSSL_jll 5.8.4+0
wolfSSL wolfSSL 5.8.4

github.com/wolfSSL/wolfssl#9148 pull request

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 10 mo ago (2025-12-11)

Exploit prediction

0.15% 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	1.0	CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA	4.0	1.0	CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/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

Affected packages

ecosystem	package	affected	fixed in
julia	wolfSSL_jll	<5.8.4+0	5.8.4+0

Affected products

wolfSSL wolfSSL

Classification

Weakness

CWE-203 Observable Discrepancy

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary