Crypto++ (aka cryptopp) through 8.9.0 has a Marvin side channel during decryption with PKCS#1 v1.5 padding.

published 2023-12-18 2 y ago modified 2026-08-13 2 mo ago also EUVD-2023-55706 , JLSEC-2026-1271

cvss: 5.9; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits: 0; none known

Patch / fix

distros 2

suse opensuse

libcryptopp SLE Module for Basesystem 15 SP7, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 8.6.0-150400.3.12.1

suse advisories SUSE-SU-2025:4310-1

libcryptopp openSUSE Tumbleweed 8.9.0-6.1

opensuse advisories openSUSE-SU-2026:10047-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-50979 updated 2026-03-17 cvss 5.9

cryptopp: side-channel leakage during decryption with PKCS#1v1.5 padding (Marvin)

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/weidai11/cryptopp/issues/1247 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
OSV	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
julia	cryptopp_jll	all versions	no fix listed

Classification

Weakness

CWE-203 Observable Discrepancy

References

github.com /weidai11/cryptopp/issues/1247
exploit, web

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.

Summary