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Fencer Vulns
critical 9.1

CVE-2020-36330 json

A flaw was found in libwebp in versions before 1.0.1.

published 2021-05-21 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-23867

cvss
9.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

A flaw was found in libwebp in versions before 1.0.1. An out-of-bounds read was found in function ChunkVerifyAndAssign. The highest threat from this vulnerability is to data confidentiality and to the service availability.

Patch / fix

  • webmproject libwebp 1.0.1
  • apple ipados 14.7
  • apple iphone_os 14.7
  • libwebp Debian 14, Debian 13, Debian 12 0.6.1-2.1

debian advisories DEBIAN-CVE-2020-36330

  • libwebp Ubuntu 18.04 LTS 0.6.1-2ubuntu0.18.04.1
  • libwebp Ubuntu 20.04 LTS 0.6.1-2ubuntu0.20.04.1
  • libwebp Ubuntu Pro 14.04 LTS 0.4.0-4ubuntu0.1~esm1
  • libwebp Ubuntu Pro 16.04 LTS 0.4.4-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2020-36330

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libwebp RHEL 8 1.0.0-5.el8

red hat advisories RHSA-2021:4231

  • libwebp SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +14 more 0.5.0-3.5.1
  • libwebp SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +12 more 0.4.3-4.7.1

suse advisories SUSE-SU-2021:1860-1SUSE-SU-2021:1830-1

  • libwebp openSUSE Leap 15.3 0.5.0-3.5.1

opensuse advisories openSUSE-SU-2021:1860-1

  • libwebp AlmaLinux 8 1.0.0-5.el8

almalinux advisories ALSA-2021:4231

  • libwebp Rocky Linux 8 1.0.0-5.el8

rocky linux advisories RLSA-2021:4231

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-2020-36330 updated cvss 9.1

libwebp: out-of-bounds read in ChunkVerifyAndAssign() in mux/muxread.c

  • Red Hat Enterprise Linux 7 firefox, libwebp, thunderbird, libwebp-java, libwebp-tools, qt5-qtimageformats
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) libwebp 1.0.0-5.el8
    fixed: vendor fix RHSA-2021:4231
  • Red Hat Enterprise Linux 8 firefox, thunderbird Red Hat Enterprise Linux 9 libwebp, libwebp-tools
    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

Exploit prediction

2.23% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:N/A:P

Affected products

  • n/a libwebp

Classification

Weakness

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.