5.9

CVE-2021-40528: gnupg libgcrypt

CVSS: 5.9v3.1MediumModified
AliasesALPINE-CVE-2021-40528MGASA-2021-0446RHSA-2022:5311
Published 06-09-2021Last modified 09-06-2025
Open JSON

Vulnerability summary

CVE-2021-40528 is a medium (CVSS 5.9) vulnerability in gnupg libgcrypt. EPSS estimates a 1.42% chance of exploitation in the next 30 days, higher than 72.4% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
5.9/10
010
Medium · v3.1 (CVE.org)
EPSS score
1.42%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
USN-5080-1USN-5080-2

Timeline

  1. 06-09-2021
    PublishedVulnerability first disclosed.
  2. 09-06-2025
    Last modifiedVulnerability information updated.

Description

The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.

CVSS metrics

7 scores · 6 sources · 2 versions

EPSS trend

Probability

1.42%

Chance of exploitation in the next 30 days

Percentile

72%

Versus all other CVEs

30-day change

0.00 pp

From 1.42% on 18-09-2026

18-09-202618-10-2026
EPSS score
1.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (ibm.github.io)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Redhat5 products
  • libgcrypt< 0:1.8.5-7.el8_6
  • libgcrypt-debuginfo< 0:1.8.5-7.el8_6
  • libgcrypt-debugsource< 0:1.8.5-7.el8_6
  • libgcrypt-devel< 0:1.8.5-7.el8_6
  • libgcrypt-devel-debuginfo< 0:1.8.5-7.el8_6
Alpine1 product
  • libgcrypt< 1.8.8-r1
Debian1 product
  • libgcrypt20< 1.8.7-6 | < 1.7.6-2+deb9u4
Gnupg1 product
Mageia1 product
  • libgcrypt< 1.8.7-1.2.mga8
Opensuse1 product
  • libgcrypt&distro=openSUSE Tumbleweed< 1.10.1-1.1
Ubuntu1 product
  • libgcrypt20< 1.6.5-2ubuntu0.6+esm1 | < 1.8.1-4ubuntu1.3 | < 1.8.1-4ubuntu1.fips.3 | All versions (No fix recorded) | < 1.8.5-5ubuntu1.1 | < 1.8.5-5ubuntu1.fips.1.1 | < 1.8.7-5ubuntu2

7 vendors · 11 products

References

21 links
Show all 21 references