CVE-2026-72522: libexpat · Out-of-bounds Read
Affects libexpatSource CVE Database V5
Not known to be exploited · CVSS 6.2 Medium : upgrade to 2.8.3 when convenient.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.8.3
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Upgrade libexpat and libexpat/libexpat to 2.8.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| libexpat projectlibexpat | Affected
| Fixed in
|
GitHublibexpat/libexpatpkg:github/libexpat/libexpatOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, users should monitor libexpat updates and consider mitigating the risk by limiting exposure to untrusted input that triggers this Unicode processing path.
Description
libexpat before 2.8.3 has an out-of-bounds read and resultant infinite loop because low surrogates are treated the same as high surrogates during Unicode processing in the *_toUtf16 functions.