Description
In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| libexpat project | libexpat | < 2.7.4 | 2.7.4 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | expat | 2.7.4-1 | — |
| Debian 13 | expat | 2.8.2-1~deb13u1 | — |
| Debian 12 | expat | 2.5.0-1+deb12u4 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tdom +5 | No fix yet | — |
| Ubuntu 26.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 25.10 | expat | 2.7.1-2ubuntu0.2 | — |
| Ubuntu 25.10 | tdom +5 | No fix yet | — |
| Ubuntu 24.04 LTS | expat | 2.6.1-2ubuntu0.4 | USN-8022-2 |
| Ubuntu 24.04 LTS | tdom +2 | No fix yet | — |
| Ubuntu 22.04 LTS | expat | 2.4.7-1ubuntu0.7 | — |
| Ubuntu 22.04 LTS | tdom +3 | No fix yet | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 18.04 LTS | gdcm +7 | No fix yet | — |
| Ubuntu 16.04 LTS | gdcm +6 | No fix yet | — |
| Ubuntu Pro 26.04 LTS | swish-e | No fix yet | — |
| Ubuntu Pro 24.04 LTS | libxmltok | 1.2-4.1ubuntu2.24.0.4.1+esm4 | — |
| Ubuntu Pro 24.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | libxmltok | 1.2-4ubuntu0.22.04.1~esm6 | — |
| Ubuntu Pro 22.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | expat | 2.2.9-1ubuntu0.8+esm1 | — |
| Ubuntu Pro 20.04 LTS | libxmltok | 1.2-4ubuntu0.20.04.1~esm6 | — |
| Ubuntu Pro 20.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | coin3 +2 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | expat | 2.2.5-3ubuntu0.9+esm3 | — |
| Ubuntu Pro 18.04 LTS | libxmltok | 1.2-4ubuntu0.18.04.1~esm6 | — |
| Ubuntu Pro 16.04 LTS | expat | 2.1.0-7ubuntu0.16.04.5+esm11 | — |
| Ubuntu Pro 16.04 LTS | libxmltok | 1.2-3ubuntu0.16.04.1~esm5 | — |
| Ubuntu Pro 16.04 LTS | vtk +6 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | expat | 2.1.0-4ubuntu1.4+esm11 | — |
| Ubuntu Pro 14.04 LTS | vtk +3 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | expat | 2.7.1-150700.3.9.2 | SUSE-SU-2026:4619-1, SUSE-SU-2026:0646-1 |
| SLES 15 SP6 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 15 SP5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 15 SP4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 12 SP5 | expat | 2.7.1-21.49.1 | SUSE-SU-2026:4615-1, SUSE-SU-2026:0647-1 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | expat | 2.7.1-160000.4.1 | SUSE-SU-2026:20627-1 |
| SLES for SAP 15 SP6 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES for SAP 15 SP5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES for SAP 15 SP4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 16.0 | expat | 2.7.1-160000.4.1 | SUSE-SU-2026:20627-1 |
| SLE Micro 6.2 | expat | 2.7.1-160000.4.1 | SUSE-SU-2026:20642-1 |
| SLE Micro 6.1 | expat | 2.7.1-slfo.1.1_4.1 | SUSE-SU-2026:24554-1, SUSE-SU-2026:20481-1 |
| SLE Micro 6.0 | expat | 2.7.1-4.1 | SUSE-SU-2026:24323-1, SUSE-SU-2026:20350-1 |
| SLE Micro 5.5 | expat | 2.7.1-150400.3.34.1 | SUSE-SU-2026:4623-1, SUSE-SU-2026:0826-1 |
| SLE Micro 5.4 | expat | 2.7.1-150400.3.34.1 | SUSE-SU-2026:4623-1, SUSE-SU-2026:0826-1 |
| SLE Micro 5.3 | expat | 2.7.1-150400.3.34.1 | SUSE-SU-2026:4623-1, SUSE-SU-2026:0826-1 |
| SLE Micro 5.2 | expat | 2.7.1-150000.3.42.1 | SUSE-SU-2026:0386-1 |
| SLE HPC 15 SP5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLE HPC 15 SP4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | expat | 2.7.4-1.1 | openSUSE-SU-2026:10144-1 |
| openSUSE Leap 16.0 | expat | 2.7.1-160000.4.1 | openSUSE-SU-2026:20306-1 |
| openSUSE Leap 15.6 | expat | 2.7.1-150400.3.34.1 | SUSE-SU-2026:0826-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | expat | 2.7.4-r0 | — |
| Alpine v3.24 | qt6-qtwebengine | 6.11.1-r2 | — |
| Alpine v3.23 | expat | 2.7.4-r0 | — |
| Alpine v3.22 | expat | 2.7.4-r0 | — |
| Alpine v3.21 | expat | 2.7.4-r0 | — |
| Alpine v3.20 | expat | 2.7.4-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | expat +2 | 2.6.3-1.amzn2023.0.4 | ALAS2023-2026-1425 |
| Amazon Linux 2023 | firefox | 140.7.0-1.amzn2023.0.2 | ALAS2023-2026-1424 |
| Amazon Linux 2 | expat +2 | 2.1.0-15.amzn2.0.6 | ALAS2-2026-3170 |
| Amazon Linux 2 | thunderbird | 140.7.1-1.amzn2.0.2 | ALAS2-2026-3171 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | expat | 2.6.4-4 | — |
| Azure Linux 2 (CBL-Mariner) | expat | 2.6.4-4 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | expat | 2.7.4-r0 | — |
Advisories 31
- ICSA-26-155-04 Hitachi Energy RTU500 (Update A) CISA ICS & IT advisories · Nov 12, 2026
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- SUSE-SU-2026:24554-1 Security update for expat SUSE / openSUSE Security Updates · Nov 7, 2026
- WID-SEC-2026-0265 expat: Schwachstelle ermöglicht Codeausführung BSI CERT-Bund (WID) · Nov 5, 2026
- WID-SEC-2026-2189 Dell PowerProtect Data Domain: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 2, 2026
- SUSE-SU-2026:24323-1 Security update for expat SUSE / openSUSE Security Updates · Oct 27, 2026
- SUSE-SU-2026:4619-1 Security update for expat SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:4623-1 Security update for expat SUSE / openSUSE Security Updates · Oct 13, 2026
- SUSE-SU-2026:4615-1 Security update for expat SUSE / openSUSE Security Updates · Oct 13, 2026
- WID-SEC-2026-2912 Dell PowerScale OneFS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 30, 2026
- WID-SEC-2026-2355 Dell integrated Dell Remote Access Controller: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jul 14, 2026
- ICSA-26-188-05 Siemens SINEC OS CISA ICS & IT advisories · Jul 7, 2026
- SSA-253495 SSA-253495: Multiple Vulnerabilities in SINEC OS before V4.0 Siemens ProductCERT · Jun 2, 2026
- USN-8022-2 expat vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- WID-SEC-2026-1204 Oracle Financial Services Applications: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 21, 2026
- WID-SEC-2026-1203 Oracle Fusion Middleware: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 21, 2026
- WID-SEC-2026-1194 Oracle Communications: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 21, 2026
- openSUSE-SU-2026:20306-1 Security update for expat SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10144-1 expat-2.7.4-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20350-1 Security update for expat SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20642-1 Security update for expat SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20627-1 Security update for expat SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20481-1 Security update for expat SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0386-1 Security update for expat SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0826-1 Security update for expat SUSE / openSUSE Security Updates · Mar 6, 2026
- SUSE-SU-2026:0647-1 Security update for expat SUSE / openSUSE Security Updates · Feb 26, 2026
- SUSE-SU-2026:0646-1 Security update for expat SUSE / openSUSE Security Updates · Feb 26, 2026
- ALAS2-2026-3170 Moderate: expat security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Feb 18, 2026
- ALAS2-2026-3171 Moderate: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Feb 18, 2026
- ALAS2023-2026-1424 Moderate: firefox security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 18, 2026
- ALAS2023-2026-1425 Moderate: expat security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 18, 2026