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Fencer Vulns
high 7.5

CVE-2025-68131 json

CBORDecoder reuse can leak shareable values across decode calls

published 2025-12-31 10 mo ago modified 2026-09-10 1 mo ago also EUVD-2025-205866 , GHSA-wcj4-jw5j-44wh , PYSEC-2025-90

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Starting in version 3.0.0 and prior to version 5.8.0, whhen a CBORDecoder instance is reused across multiple decode operations, values marked with the shareable tag (28) persist in memory and can be accessed by subsequent CBOR messages using the sharedref tag (29). This allows an attacker-controlled message to read data from previously decoded messages if the decoder is reused across trust boundaries. Version 5.8.0 patches the issue.

Patch / fix

  • pypi cbor2 5.8.0
  • agronholm cbor2 5.8.0
  • cbor2 Debian 14 5.8.0-1

debian advisories DEBIAN-CVE-2025-68131

  • python-cbor2 SLES for SAP applications 16.0, SLES 16.0 5.6.5-160000.4.1

suse advisories SUSE-SU-2026:21139-1

  • python-cbor2 openSUSE Leap 16.0 5.6.5-160000.4.1
  • python-cbor2 openSUSE Tumbleweed 5.8.0-2.1

opensuse advisories openSUSE-SU-2026:20468-1openSUSE-SU-2026:10014-1

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-2025-68131 updated cvss 5.3

cbor2: cbor2: Information Disclosure via shared memory in CBORDecoder reuse

  • Red Hat AI Inference Server rhaiis/vllm-tpu-rhel9, rhaiis/vllm-spyre-rhel9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-vllm-cuda-rhel9, rhoai/odh-vllm-rocm-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat AI Inference Server 3.2 rhaiis 1774351144, rhaiis 1774547384, rhaiis 1775252598
    fixed: vendor fix RHSA-2026:6761
  • Red Hat OpenShift AI 2.25 rhoai 1776259063
    fixed: vendor fix RHSA-2026:10184
  • Red Hat OpenShift AI 2.25 rhoai 1775144403, rhoai 1776243157, rhoai 1776243163, rhoai 1776243192, rhoai 1776243217, rhoai 1776243229, +70 more
    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
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
10 mo ago

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/agronholm/cbor2/pull/268 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/agronholm/cbor2/security/advisories/GHSA-wcj4-jw5j-44wh referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA 4.0 5.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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:H/I:N/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi cbor2
>=3.0.0, <5.8.0
5.8.0

Affected products

  • agronholm cbor2

Classification

Weakness
  • CWE-212 Improper Removal of Sensitive Information Before Storage or Transfer

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.