01 Record

CVE-2026-102633

libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc

HighPUBLISHEDCNA: VulnCheck

CNA base score8.2 CVSS v4.0CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

View raw JSON

02 Description

libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.36% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 30.3% of scored records. A rank, not a probability.

NVD base score

8.2 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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 analysis status

Awaiting Analysis. NVD last modified this record on 2026-09-29.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2026-09-29 16:04Z29 DAYS AGO

Last updated

2026-09-29 16:52Z29 DAYS AGO

Reserved

2026-09-29

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.2)

CNA CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Weaknesses

CWE-190Integer Overflow or WraparoundBase

Data version

5.2

Document digest

33c0237ac53fe88825bbb0ed306afba7a37ce56105202428c4c99bf0df608d05

05 Affected products

VendorProductVersionsPlatforms

libexpatlibexpat2.7.2 to 2.8.5—

06 References

github.comPull Request #1392https://github.com/libexpat/libexpat/pull/1392issue-trackingpatch
github.comPatch Commithttps://github.com/libexpat/libexpat/commit/209801d7fbaf07ab74bae8cb32dd2ab9e5846118patch
github.comhttps://github.com/libexpat/libexpat/blob/R_2_8_5/expat/lib/xmlparse.c#L1003technical-description
github.comhttps://github.com/libexpat/libexpatproduct
www.vulncheck.comVulnCheck Advisory: libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_reallochttps://www.vulncheck.com/advisories/libexpat-2.7.2-through-2.8.5-integer-overflow-in-expat-reallocthird-party-advisory

07 Fixed in

AlmaLinux 9

expat
Fixed in 2.5.0-6.el9_8.7
expat-devel
Fixed in 2.5.0-6.el9_8.7

AlmaLinux 10

expat
Fixed in 2.7.3-1.el10_2.7

CloudLinux 9

expat
Fixed in 2.5.0-6.el9_8.7
expat-devel
Fixed in 2.5.0-6.el9_8.7

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

CloudLinux 10

expat
Fixed in 2.7.3-1.el10_2.7

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Debian 12

expat
Fixed in 2.5.0-1+deb12u5

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

expat
Fixed in 2.9.0-1~deb13u1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

expat
Fixed in 2.8.5-2

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.