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Fencer Vulns
high 7.5

CVE-2026-41676 json

rust-openssl: Deriver::derive and PkeyCtxRef::derive can overflow short buffers on OpenSSL 1.1.1

published 2026-04-22 6 mo ago modified 2026-09-10 1 mo ago also GHSA-pqf5-4pqq-29f5 , EUVD-2026-25582

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.27 to before 0.10.78, Deriver::derive (and PkeyCtxRef::derive) sets len = buf.len() and passes it as the in/out length to EVP_PKEY_derive, relying on OpenSSL to honor it. On OpenSSL 1.1.x, X25519, X448, DH and HKDF-extract ignore the incoming *keylen, unconditionally writing the full shared secret (32/56/prime-size bytes). A caller passing a short slice gets a heap/stack overflow from safe code. OpenSSL 3.x providers do check, so this only impacts older OpenSSL. This vulnerability is fixed in 0.10.78.

Patch / fix

  • crates.io openssl 0.10.78
  • rust-openssl_project rust-openssl 0.10.78
  • rust-openssl Debian 14 0.10.78-1

debian advisories DEBIAN-CVE-2026-41676

  • rustup SLES for SAP applications 16.0, SLES 16.0 1.29.1~0-160000.1.1
  • sccache SLES for SAP applications 16.0, SLES 16.0 0.18.0~2-160000.1.1
  • clamav SLE Micro 5.5 1.5.3-150400.13.8.1
  • aws-nitro-enclaves-cli SLES 16.0, SLES for SAP applications 16.0 1.5.0~git0.2950b36-160000.1.1
  • aws-nitro-enclaves-cli SLE Module for Public Cloud 15 SP7, SLE Module for Public Cloud 15 SP6 1.5.0~git0.2950b36-150600.10.15.1
  • himmelblau SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES 15 SP6-LTSS +3 more 2.3.14+git0.e23b4c54-150500.11.12.1
  • s390-tools SLE Micro 5.5 2.31.0-150500.9.32.1
  • s390-tools SLE Micro 5.4, SLE Micro 5.3 2.31.0-150400.7.34.1

suse advisories SUSE-SU-2026:24014-1SUSE-SU-2026:23983-1SUSE-SU-2026:2834-2SUSE-SU-2026:23643-1SUSE-SU-2026:23659-1SUSE-SU-2026:3992-1

  • rustup openSUSE Leap 16.0 1.29.1~0-160000.1.1
  • sccache openSUSE Leap 16.0 0.18.0~2-160000.1.1
  • sdbootutil openSUSE Leap 16.0 1+git20260908.c641fc2-160000.1.1
  • aws-nitro-enclaves-cli openSUSE Leap 16.0 1.5.0~git0.2950b36-160000.1.1
  • libkrun openSUSE Leap 16.0 1.4.10-160000.3.1
  • afterburn openSUSE Leap 16.0 5.10.0.git73.b97f772-160000.1.1
  • afterburn openSUSE Tumbleweed 5.10.0.git73.b97f772-1.1
  • python-cryptography openSUSE Leap 16.0 44.0.3-160000.4.1

opensuse advisories openSUSE-SU-2026:22016-1openSUSE-SU-2026:21982-1openSUSE-SU-2026:21933-1openSUSE-SU-2026:21782-1openSUSE-SU-2026:21464-1openSUSE-SU-2026:21386-1

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-2026-41676 updated cvss 8.6

rust-openssl: rust-openssl: Memory overflow allows arbitrary code execution or denial of service

  • 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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
6 mo ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.2 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U
CNA 4.0 7.2 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/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 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
crates.io openssl
>=0.9.27, <0.10.78
0.10.78

Affected products

  • rust-openssl rust-openssl

Classification

Weakness
  • CWE-787 Out-of-bounds Write
  • CWE-131 Incorrect Calculation of Buffer Size

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.