3.7

CVE-2026-43860: mutt Off-by-one Error

Deferred
AliasesUBUNTU-CVE-2026-43860DEBIAN-CVE-2026-43860
Published 04-05-2026Last modified 04-05-2026

Vulnerability summary

CVE-2026-43860 is a low (CVSS 3.7) Off-by-one Error vulnerability in mutt. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 3.7, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
3.7/10
010
Low · v3.1 (CVE.org)
EPSS score
0.16%
0%100%
Low · -0.09 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:21016-1SUSE-SU-2026:22340-1

Timeline

  1. 04-05-2026
    PublishedVulnerability first disclosed.
  2. 04-05-2026
    Last modifiedVulnerability information updated.

Description

mutt before 2.3.2 sometimes truncates the hash_passwd by one byte for IMAP auth_cram MD5 digest.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

Decrease -0.09 pp

From 0.26% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Debian1 product
  • muttAll versions (No fix recorded) | < 2.2.13-1+deb13u1 | < 2.3.2-1
Mutt1 product
Ubuntu1 product
  • muttAll versions (No fix recorded)

3 vendors · 3 products

References

4 links