CVE-2023-4863: Google Chrome · Heap buffer overflow
Affects Google ChromeSource CVE Database V5
Exploited in the wild · KEV due 4 Oct 2023 · 99% EPSS : upgrade to 1.3.2 now.
Data as of 25 Oct 2026, 19:02 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else.
- EPSS
- 99.9% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.3.2, 116.0.5845.187
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 12 Sep 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 1 day after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Chrome
, 3 days before disclosure
CVE published
on cve.org
, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 1 day after disclosure
KEV remediation due
US federal deadline
, 22 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade webmproject/libwebp to 1.3.2; debian/chrome to 116.0.5845.187.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubwebmproject/libwebppkg:github/webmproject/libwebpOther threats | Affected
| Fixed in
|
Debiandebian/chromepkg:deb/debian/chromeOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
Heap buffer overflow in libwebp in Google Chrome prior to 116.0.5845.187 and libwebp 1.3.2 allowed a remote attacker to perform an out of bounds memory write via a crafted HTML page. (Chromium security severity: Critical)
References
- chromereleases.googleblog.com/2023/09/stable-channel-update-for-desktop_11.html (opens in a new tab)
- crbug.com/1479274 (opens in a new tab)
- en.bandisoft.com/honeyview/history/ (opens in a new tab)
- stackdiary.com/critical-vulnerability-in-webp-codec-cve-2023-4863/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2023-40/ (opens in a new tab)
- github.com/webmproject/libwebp/commit/902bc9190331343b2017211debcec8d2ab87e17a (opens in a new tab)
- msrc.microsoft.com/update-guide/vulnerability/CVE-2023-4863 (opens in a new tab)
- security-tracker.debian.org/tracker/CVE-2023-4863 (opens in a new tab)
- bugzilla.suse.com/show_bug.cgi?id=1215231 (opens in a new tab)
- news.ycombinator.com/item?id=37478403 (opens in a new tab)
- bleepingcomputer.com/news/google/google-fixes-another-chrome-zero-day-bug-exploited-in-attacks/ (opens in a new tab)
- debian.org/security/2023/dsa-5496 (opens in a new tab)
- debian.org/security/2023/dsa-5497 (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OZDGWWMJREPAGKWCJKSCM4WYLANSKIFX/ (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FYYKLG6CRGEDTNRBSU26EEWAO6D6U645/ (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PYZV7TMKF4QHZ54SFJX54BDN52VHGGCX/ (opens in a new tab)
- lists.debian.org/debian-lts-announce/2023/09/msg00015.html (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WHOLML7N2G5KCAZXFWC5IDFFHSQS5SDB/ (opens in a new tab)
- debian.org/security/2023/dsa-5498 (opens in a new tab)
- security.gentoo.org/glsa/202309-05 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2023/09/msg00016.html (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6T655QF7CQ3DYAMPFV7IECQYGDEUIVVT/ (opens in a new tab)
- adamcaudill.com/2023/09/14/whose-cve-is-it-anyway/ (opens in a new tab)
- github.com/webmproject/libwebp/releases/tag/v1.3.2 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2023/09/msg00017.html (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KUQ7CTX3W372X3UY56VVNAHCH6H2F4X3/ (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/21/4 (opens in a new tab)
- blog.isosceles.com/the-webp-0day/ (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/1 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/3 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/4 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/5 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/8 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/7 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/22/6 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/26/1 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/26/7 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/28/1 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/28/2 (opens in a new tab)
- openwall.com/lists/oss-security/2023/09/28/4 (opens in a new tab)
- security.netapp.com/advisory/ntap-20230929-0011/ (opens in a new tab)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WTRUIS3564P7ZLM2S2IH4Y4KZ327LI4I/ (opens in a new tab)
- sethmlarson.dev/security-developer-in-residence-weekly-report-16 (opens in a new tab)
- bentley.com/advisories/be-2023-0001/ (opens in a new tab)
- security.gentoo.org/glsa/202401-10 (opens in a new tab)
- vicarius.io/vsociety/posts/zero-day-webp-vulnerability-cve-2023-4863 (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4863 (opens in a new tab)