CVE-2026-72522
published 2026-08-10CVE-2026-72522: 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…
PriorityP422medium6.2CVSS 3.1
AVLACLPRNUINSUCNINAH
EPSS
0.18%
7.5th percentile
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.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | expat | — | — |
| libexpat_project | libexpat | < 2.8.3 | 2.8.3 |
| mozilla | firefox | — | — |
| mozilla | thunderbird | — | — |
CVSS provenance
nvdv3.16.2MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat6.2MEDIUM
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VulDB
Libexpat up to 2.8.2 Unicode *_toUtf16 out-of-bounds (EUVD-2026-54990 / WID-SEC-2026-2718)
vuldb·2026-08-11·CVSS 6.2
CVE-2026-72522 [MEDIUM] Libexpat up to 2.8.2 Unicode *_toUtf16 out-of-bounds (EUVD-2026-54990 / WID-SEC-2026-2718)
A vulnerability categorized as critical has been discovered in Libexpat up to 2.8.2. This affects the function *_toUtf16 of the component Unicode Handler. Such manipulation leads to out-of-bounds read.
This vulnerability is referenced as CVE-2026-72522. It is possible to launch the attack remotely. No exploit is available.
It is advisable to upgrade the affected component.
GHSA
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.
ghsa_unreviewed·2026-08-10
CVE-2026-72522 [MEDIUM] CWE-125 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.
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.
Red Hat
expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling
vendor_redhat·2026-08-10·CVSS 6.2
CVE-2026-72522 [MEDIUM] CWE-125 expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling
expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling
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.
A flaw in libexpat's _toUtf16 functions mishandles Unicode low surrogates by treating them as high surrogates. An attacker can exploit the resulting out-of-bounds read to trigger an infinite loop, causing a denial of service (DoS).
Statement: A denial of service (DoS) flaw was found in libexpat's handling of Unicode surrogate pairs. An attacker providing specially crafted XML input to an application parsing untrusted data can trigger an out-of-bounds read and an infinite loop, leading to high CPU usage and system resour
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-72522 mingw-expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling [fedora-all]
bugzilla·2026-08-11·CVSS 6.2
CVE-2026-72522 [MEDIUM] CVE-2026-72522 mingw-expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling [fedora-all]
CVE-2026-72522 mingw-expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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.
Bugzilla
CVE-2026-72522 expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling
bugzilla·2026-08-10·CVSS 6.2
CVE-2026-72522 [MEDIUM] CVE-2026-72522 expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling
CVE-2026-72522 expat: libexpat: Denial of Service due to incorrect Unicode surrogate handling
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.
2026-08-10
Published