Linux · 
Ubuntu · Package update · August 20, 2026
Ubuntu · Package update · August 20, 2026expat 2.2.5-3ubuntu0.9+esm5: expat 2.2.5-3ubuntu0.9+esm5 for Ubuntu 18.04.6 LTS (bionic)
expat 2.2.5-3ubuntu0.9+esm5, released August 20, 2026, fixes 11 CVEs in expat. None of them is reported as exploited. Patch Radar priority: High. The product is no longer supported.
HighUnsupported product
CVEs closed
11
None rated Critical
Exploited
0
None reported
Highest CVSS
7.8
Base score, 0 to 10
Highest EPSS
0.0086
58th percentile
Priority of the 11 CVEs
Patch now 0
Urgent 0
High 2
Routine 9
Fixed package versions
| Product | Release | Fixed in |
|---|---|---|
| expat | Ubuntu 18.04.6 LTS (bionic) | 2.2.5-3ubuntu0.9+esm5 |
CVEs this fix closes
| Priority | CVE | Title | CVSS | EPSS | Exploitation |
|---|---|---|---|---|---|
| High | CVE-2026-66046 | Expat Denial of Service via storeAtts() Quadratic Complexity | 7.5 | 0.0086 | None reported |
| High | CVE-2026-76957 | libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412. | 7.8 | 0.0012 | None reported |
| Routine | CVE-2026-76641 | expat: out-of-bounds read vulnerability that allows attackers to trigger | n/a | 0.0035 | None reported |
| Routine | CVE-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 processing in the *_toUtf16 functions. | 6.2 | 0.0019 | None reported |
| Routine | CVE-2026-56406 | libexpat before 2.8.2 has an integer overflow in XML_ParseBuffer because it lacked a check that was present in XML_Parse. | 6.9 | 0.0019 | None reported |
| Routine | CVE-2026-56407 | libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen. | 6.9 | 0.0019 | None reported |
| Routine | CVE-2026-56131 | libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation). | 4.9 | 0.0018 | None reported |
| Routine | CVE-2026-56132 | In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is mishandled when there is data-structure sharing across parsers. | 6.9 | 0.0016 | None reported |
| Routine | CVE-2026-56410 | xmlwf in libexpat before 2.8.2 has an integer overflow in resolveSystemId. | 6.9 | 0.0015 | None reported |
| Routine | CVE-2026-56411 | xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations. | 6.9 | 0.0015 | None reported |
| Routine | CVE-2026-56409 | xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used. | 6.5 | 0.0014 | None reported |
Showing 1 to 11 of 11
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