[UPDATE] [low] libexpat: Multiple vulnerabilities allow denial of service
A local attacker can exploit multiple vulnerabilities in libexpat to conduct a denial of service attack.
CSIRTS triage
- What
- Multiple vulnerabilities in libexpat can be exploited by a local attacker to conduct a denial of service attack.
- Who is affected
- Local deployments of libexpat are affected by these vulnerabilities.
- Urgency
- Remediation is low urgency due to the low severity of the vulnerabilities.
- Action
- Update to the latest version of libexpat.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0733
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-327760.16% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all scored CVEs.
- Low exploitation riskCVE-2026-327770.22% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 12% of all scored CVEs.
- Low exploitation riskCVE-2026-327780.17% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 7% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-32776 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-32777 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-32778 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
Recent advisories for libexpat
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- medium[UPDATE] [medium] libexpat: Multiple vulnerabilities allow unspecified attackcert-bund · 2026-07-22
- mediumCVE-2026-56131: libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from wit…msrc · 2026-06-09
- mediumCVE-2026-56407: libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue …msrc · 2026-06-09
- mediumCVE-2026-56410: xmlwf in libexpat before 2.8.2 has an integer overflow in resolveSystemId.msrc · 2026-06-09
- mediumCVE-2026-56403: libexpat before 2.8.2 has an integer overflow in storeAtts.msrc · 2026-06-09
- mediumCVE-2026-56132: In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c beca…msrc · 2026-06-09
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