7.5

CVE-2026-57585: MessagePack: Out-of-bounds read/crash on Unpacker reuse after caught error

Analyzed
AliasesSUSE-SU-2026:22704-1SUSE-SU-2026:23169-1SUSE-SU-2026:3113-1
Published 30-06-2026Last modified 01-07-2026

Vulnerability summary

CVE-2026-57585 is a high (CVSS 7.5) Use After Free vulnerability in msgpack messagepack. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 42% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.49%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 30-06-2026
    PublishedVulnerability first disclosed.
  2. 01-07-2026
    Last modifiedVulnerability information updated.

Description

MessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.1, there is an Out-of-bounds read/crash on Unpacker reuse after a caught error, potentially leading to a DoS attack. If the Unpacker is used repeatedly after an error occurs, the process may crash with a SEGV. This issue has been fixed in version 1.2.1.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.49%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.49% 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.

Suse18 products
  • python-msgpack-python&distro=SUSE Manager Client Tools 12< 0.4.6-8.8.1
  • python-msgpack&distro=SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS< 0.5.6-150100.3.6.1 | < 1.0.7-150400.10.9.1
  • python-msgpack&distro=SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS< 0.5.6-150100.3.6.1 | < 1.0.7-150400.10.9.1
  • python-msgpack&distro=SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS< 0.5.6-150100.3.6.1 | < 1.0.7-150400.10.9.1
  • python-msgpack&distro=SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS< 0.5.6-150100.3.6.1 | < 1.0.7-150400.10.9.1
Ubuntu3 products
  • python-msgpackAll versions (No fix recorded)
  • python-pipAll versions (No fix recorded)
  • python-srslyAll versions (No fix recorded)
Msgpack2 products
Opensuse2 products
  • python-msgpack&distro=openSUSE Leap 16.0< 1.1.0-160000.3.1
  • python-msgpack&distro=openSUSE Tumbleweed< 1.2.1-1.1
Debian1 product
  • python-msgpackAll versions (No fix recorded) | < 1.1.2-3
PyPI1 product
  • msgpack< 1.2.1

6 vendors · 27 products

References

16 links
Show all 16 references