CVE-2022-43680

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations.

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations.

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations.

expat is a stream-oriented XML parser library written in C. expat excels with files too large to fit RAM, and where performance and flexibility are crucial.

Security Fix(es):

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations.(CVE-2022-43680)

Expat is a C library for parsing XML documents.

Security Fix(es):

• expat: use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (CVE-2022-43680)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Expat is a C library for parsing XML documents.

Security Fix(es):

• expat: use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (CVE-2022-43680)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations.

Expat is a C library for parsing XML documents.

Security Fix(es):

• expat: use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (CVE-2022-43680)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Expat is a C library for parsing XML documents.

Security Fix(es):

• expat: use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (CVE-2022-43680)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

In parserCreate of xmlparse.c, there is a possible use after free that could lead to remote code execution with no additional execution privileges needed. User interaction is not needed for exploitation.

• CVE-2022-43680: Fix overeager DTD destruction

• SECURITY UPDATE: Fix overeager DTD destruction
  • debian/patches/CVE-2022-43680: Fix heap use-after-free after overeager destruction of a shared DTD in function XML_ExternalEntityParserCreate in out-of-memory situations
  • CVE-2022-43680

• CVE-2022-43680: Fix overeager DTD destruction

• CVE-2022-43680: Fix overeager DTD destruction

• CVE-2022-43680: Fix overeager DTD destruction

• CVE-2022-23990: lib: prevent integer overflow in function doProlog
• CVE-2022-43680: fix overeager DTD destruction in XML_ExternalEntityParserCreate

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations. (CVE-2022-43680)

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations (CVE-2022-43680).

Service Workers should not be able to infer information about opaque cross-origin responses; but timing information for cross-origin media combined with Range requests might have allowed them to determine the presence or length of a media file (CVE-2022-45403).

Through a series of popup and window.print() calls, an attacker can cause a window to go fullscreen without the user seeing the notification prompt, resulting in potential user confusion or spoofing attacks (CVE-2022-45404).

Freeing arbitrary nsIInputStream's on a different thread than creation could have led to a use-after-free and potentially exploitable crash (CVE-2022-45405).

If an out-of-memory condition occurred when creating a JavaScript global, a JavaScript realm may be deleted while references to it lived on in a BaseShape. This could lead to a use-after-free causing a potentially exploitable crash (CVE-2022-45406).

Through a series of popups that reuse windowName, an attacker can cause a window to go fullscreen without the user seeing the notification prompt, resulting in potential user confusion or spoofing attacks (CVE-2022-45408).

The garbage collector could have been aborted in several states and zones and GCRuntime::finishCollection may not have been called, leading to a use-after-free and potentially exploitable crash (CVE-2022-45409).

When a ServiceWorker intercepted a request with FetchEvent, the origin of the request was lost after the ServiceWorker took ownership of it. This had the effect of negating SameSite cookie protections. This was addressed in the spec and then in browsers (CVE-2022-45410).

Cross-Site Tracing occurs when a server will echo a request back via the Trace method, allowing an XSS attack to access to authorization headers and cookies inaccessible to JavaScript (such as cookies protected by HTTPOnly). To mitigate this attack, browsers placed limits on fetch() and XMLHttpRequest; however some webservers have implemented non-standard headers such as X-Http-Method-Override that override the HTTP method, and made this attack possible again. Firefox has applied the same mitigations to the use of this and similar headers (CVE-2022-45411).

When resolving a symlink such as file:///proc/self/fd/1, an error message may be produced where the symlink was resolved to a string containing unitialized memory in the buffer (CVE-2022-45412).

Keyboard events reference strings like "KeyA" that were at fixed, known, and widely-spread addresses. Cache-based timing attacks such as Prime+Probe could have possibly figured out which keys were being pressed (CVE-2022-45416).

If a custom mouse cursor is specified in CSS, under certain circumstances the cursor could have been drawn over the browser UI, resulting in potential user confusion or spoofing attacks (CVE-2022-45418).

Use tables inside of an iframe, an attacker could have caused iframe contents to be rendered outside the boundaries of the iframe, resulting in potential user confusion or spoofing attacks (CVE-2022-45420).

Mozilla developers Andrew McCreight and Gabriele Svelto reported memory safety bugs present in Firefox ESR 102.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code (CVE-2022-45421).

This update fixes the vulnerabilities by no longer building with the vulnerable bundled libexpat version.

These are all security issues fixed in the expat-2.5.0-1.1 package on the GA media of openSUSE Tumbleweed.

This update for expat fixes the following issues:

• CVE-2022-43680: Fixed use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (bsc#1204708).

This update for expat fixes the following issues:

• CVE-2022-43680: Fixed use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (bsc#1204708).

This update for expat fixes the following issues:

• CVE-2022-43680: Fixed use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate (bsc#1204708).

This update for expat fixes the following issues:

• CVE-2025-59375: denial of service (resource consumption) caused by processing malformed small documents (bsc#1249584).
• CVE-2026-24515: NULL dereference (CWE-476) due to function XML_ExternalEntityParserCreate() failing to copy the encoding handler data passed to XML_SetUnknownEncodingHandler() from the parent to the subparser (bsc#1257144).
• CVE-2026-25210: lack of buffer size check can lead to an integer overflow (bsc#1257496).
• CVE-2026-32776: NULL pointer dereference when processing empty external parameter entities inside an entity declaration value (bsc#1259726).
• CVE-2026-32777: denial of service due to infinite loop in DTD content parsing (bsc#1259711).
• CVE-2026-32778: NULL pointer dereference in setContext on retry after an out-of-memory condition (bsc#1259729).
• CVE-2026-41080: crafted XML document can cause a denial of service (bsc#1262263).
• CVE-2026-45186: denial of service via moderately sized crafted XML input (bsc#1264713).
• CVE-2026-50219: lack of handler call depth tracking for calls to XML_* functions from within handlers in cases of a policy violation (bsc#1267631).
• CVE-2026-56131: lack of handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation (bsc#1268572).
• CVE-2026-56132: heap-based buffer overflow in doProlog in xmlparse.c (bsc#1268573).
• CVE-2026-56403,CVE-2026-56404,CVE-2026-56405,CVE-2026-56406, CVE-2026-56407,CVE-2026-56408,CVE-2026-56409,CVE-2026-56410, CVE-2026-56411,CVE-2026-56412: multiple integer overflow vulnerabilities (bsc#1275115).
• CVE-2026-66046: denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function (bsc#1275732).
• CVE-2026-72522: out-of-bounds read and resultant infinite loop due to low surrogates being treated the same as high surrogates during Unicode processing (bsc#1275594).
• CVE-2026-76641: out-of-bounds read vulnerability that allows attackers to trigger memory corruption (bsc#1275915).
• CVE-2026-76956: denial of service via hash flooding attacks (bsc#1275860).
• CVE-2026-76957: lack of handler call depth tracking with custom encoding callbacks. Thus, a use- after-free can occur (bsc#1275859).
• CVE-2026-77214: out-of-bounds read due to insufficient checks in XML_ParseBuffer() (bsc#1284334).
• CVE-2026-93990: fails to validate low surrogates following high surrogates in UTF-16 input (bsc#1282347).
• CVE-2026-102633: Denial of Service via integer overflow in expat_realloc (bsc#1283493).

Update to 2.8.5 (jsc#PED-16154):

• Bug fixes:
• Fix an OOM-related memory leak on a failed overflow check
• Fix memory alignment for architectures with 128bit pointers
• Mark XML_SetHashSalt deprecated
• CMake: only add /source-charset:utf-8 when /utf-8 is not present
• lib: resolve undefined behavior from overshifting a signed int
• lib: support read-only hash table lookup with non-zero-terminated keys
• lib: use a C99 bool for ENTITY.open
• version info bumped from 13:3:12 to 13:4:12
• fix support for 2+ GiB documents (regression from 2.8.2)
• reject empty version in the XML declaration
• fix printf format for AIX
• CMake|AIX: enable EXPAT_DEV_URANDOM by default
• version info bumped from 13:2:12 to 13:3:12
• Existing API function XML_SetHashSalt is now deprecated
• because of its limitations, and its use should be
• considered a vulnerability. Please either use the new API
• function XML_SetHashSalt16Bytes (with known-high-quality
• entropy input only!) instead, or leave the derivation of
• a 16-bytes hash salt from high quality entropy to Expat's
• internal machinery (by not calling either of the two
• XML_SetHashSalt* functions).
• xmlwf: Fix a memory leak
• WASI: Fix format specifiers for 32bit WASI SDK
• Fix alignment of internal allocations for some non-amd64 architectures (e.g. sparc32); fixes up on the fix to CVE-2025-59375 (of Expat 2.7.2)
• Fix a class of…

This update for expat fixes the following issues:

• CVE-2025-59375: denial of service (resource consumption) caused by processing malformed small documents (bsc#1249584).
• CVE-2026-24515: NULL dereference (CWE-476) due to function XML_ExternalEntityParserCreate() failing to copy the encoding handler data passed to XML_SetUnknownEncodingHandler() from the parent to the subparser (bsc#1257144).
• CVE-2026-25210: lack of buffer size check can lead to an integer overflow (bsc#1257496).
• CVE-2026-32776: NULL pointer dereference when processing empty external parameter entities inside an entity declaration value (bsc#1259726).
• CVE-2026-32777: denial of service due to infinite loop in DTD content parsing (bsc#1259711).
• CVE-2026-32778: NULL pointer dereference in setContext on retry after an out-of-memory condition (bsc#1259729).
• CVE-2026-41080: crafted XML document can cause a denial of service (bsc#1262263).
• CVE-2026-45186: denial of service via moderately sized crafted XML input (bsc#1264713).
• CVE-2026-50219: lack of handler call depth tracking for calls to XML_* functions from within handlers in cases of a policy violation (bsc#1267631).
• CVE-2026-56131: lack of handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation (bsc#1268572).
• CVE-2026-56132: heap-based buffer overflow in doProlog in xmlparse.c (bsc#1268573).
• CVE-2026-56403,CVE-2026-56404,CVE-2026-56405,CVE-2026-56406, CVE-2026-56407,CVE-2026-56408,CVE-2026-56409,CVE-2026-56410, CVE-2026-56411,CVE-2026-56412: multiple integer overflow vulnerabilities (bsc#1275115).
• CVE-2026-66046: denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function (bsc#1275732).
• CVE-2026-72522: out-of-bounds read and resultant infinite loop due to low surrogates being treated the same as high surrogates during Unicode processing (bsc#1275594).
• CVE-2026-76641: out-of-bounds read vulnerability that allows attackers to trigger memory corruption (bsc#1275915).
• CVE-2026-76956: denial of service via hash flooding attacks (bsc#1275860).
• CVE-2026-76957: lack of handler call depth tracking with custom encoding callbacks. Thus, a use- after-free can occur (bsc#1275859).
• CVE-2026-77214: out-of-bounds read due to insufficient checks in XML_ParseBuffer() (bsc#1284334).
• CVE-2026-93990: fails to validate low surrogates following high surrogates in UTF-16 input (bsc#1282347).
• CVE-2026-102633: Denial of Service via integer overflow in expat_realloc (bsc#1283493).

Update to 2.8.5 (jsc#PED-16154):

• Bug fixes:
• Fix an OOM-related memory leak on a failed overflow check
• Fix memory alignment for architectures with 128bit pointers
• Mark XML_SetHashSalt deprecated
• CMake: only add /source-charset:utf-8 when /utf-8 is not present
• lib: resolve undefined behavior from overshifting a signed int
• lib: support read-only hash table lookup with non-zero-terminated keys
• lib: use a C99 bool for ENTITY.open
• version info bumped from 13:3:12 to 13:4:12
• fix support for 2+ GiB documents (regression from 2.8.2)
• reject empty version in the XML declaration
• fix printf format for AIX
• CMake|AIX: enable EXPAT_DEV_URANDOM by default
• version info bumped from 13:2:12 to 13:3:12
• Existing API function XML_SetHashSalt is now deprecated
• because of its limitations, and its use should be
• considered a vulnerability. Please either use the new API
• function XML_SetHashSalt16Bytes (with known-high-quality
• entropy input only!) instead, or leave the derivation of
• a 16-bytes hash salt from high quality entropy to Expat's
• internal machinery (by not calling either of the two
• XML_SetHashSalt* functions).
• xmlwf: Fix a memory leak
• WASI: Fix format specifiers for 32bit WASI SDK
• Fix alignment of internal allocations for some non-amd64 architectures (e.g. sparc32); fixes up on the fix to CVE-2025-59375 (of Expat 2.7.2)
• Fix a class of…

This update for expat fixes the following issues:

• CVE-2025-59375: denial of service (resource consumption) caused by processing malformed small documents (bsc#1249584).
• CVE-2026-24515: NULL dereference (CWE-476) due to function XML_ExternalEntityParserCreate() failing to copy the encoding handler data passed to XML_SetUnknownEncodingHandler() from the parent to the subparser (bsc#1257144).
• CVE-2026-25210: lack of buffer size check can lead to an integer overflow (bsc#1257496).
• CVE-2026-32776: NULL pointer dereference when processing empty external parameter entities inside an entity declaration value (bsc#1259726).
• CVE-2026-32777: denial of service due to infinite loop in DTD content parsing (bsc#1259711).
• CVE-2026-32778: NULL pointer dereference in setContext on retry after an out-of-memory condition (bsc#1259729).
• CVE-2026-41080: crafted XML document can cause a denial of service (bsc#1262263).
• CVE-2026-45186: denial of service via moderately sized crafted XML input (bsc#1264713).
• CVE-2026-50219: lack of handler call depth tracking for calls to XML_* functions from within handlers in cases of a policy violation (bsc#1267631).
• CVE-2026-56131: lack of handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation (bsc#1268572).
• CVE-2026-56132: heap-based buffer overflow in doProlog in xmlparse.c (bsc#1268573).
• CVE-2026-56403,CVE-2026-56404,CVE-2026-56405,CVE-2026-56406, CVE-2026-56407,CVE-2026-56408,CVE-2026-56409,CVE-2026-56410, CVE-2026-56411,CVE-2026-56412: multiple integer overflow vulnerabilities (bsc#1275115).
• CVE-2026-66046: denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function (bsc#1275732).
• CVE-2026-72522: out-of-bounds read and resultant infinite loop due to low surrogates being treated the same as high surrogates during Unicode processing (bsc#1275594).
• CVE-2026-76641: out-of-bounds read vulnerability that allows attackers to trigger memory corruption (bsc#1275915).
• CVE-2026-76956: denial of service via hash flooding attacks (bsc#1275860).
• CVE-2026-76957: lack of handler call depth tracking with custom encoding callbacks. Thus, a use- after-free can occur (bsc#1275859).
• CVE-2026-77214: out-of-bounds read due to insufficient checks in XML_ParseBuffer() (bsc#1284334).
• CVE-2026-93990: fails to validate low surrogates following high surrogates in UTF-16 input (bsc#1282347).
• CVE-2026-102633: Denial of Service via integer overflow in expat_realloc (bsc#1283493).

Update to 2.8.5 (jsc#PED-16154):

• Bug fixes:
• Fix an OOM-related memory leak on a failed overflow check
• Fix memory alignment for architectures with 128bit pointers
• Mark XML_SetHashSalt deprecated
• CMake: only add /source-charset:utf-8 when /utf-8 is not present
• lib: resolve undefined behavior from overshifting a signed int
• lib: support read-only hash table lookup with non-zero-terminated keys
• lib: use a C99 bool for ENTITY.open
• version info bumped from 13:3:12 to 13:4:12
• fix support for 2+ GiB documents (regression from 2.8.2)
• reject empty version in the XML declaration
• fix printf format for AIX
• CMake|AIX: enable EXPAT_DEV_URANDOM by default
• version info bumped from 13:2:12 to 13:3:12
• Existing API function XML_SetHashSalt is now deprecated
• because of its limitations, and its use should be
• considered a vulnerability. Please either use the new API
• function XML_SetHashSalt16Bytes (with known-high-quality
• entropy input only!) instead, or leave the derivation of
• a 16-bytes hash salt from high quality entropy to Expat's
• internal machinery (by not calling either of the two
• XML_SetHashSalt* functions).
• xmlwf: Fix a memory leak
• WASI: Fix format specifiers for 32bit WASI SDK
• Fix alignment of internal allocations for some non-amd64 architectures (e.g. sparc32); fixes up on the fix to CVE-2025-59375 (of Expat 2.7.2)
• Fix a class of…

USN-5638-1 fixed a vulnerability in Expat. This update provides the corresponding updates for Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 22.04 LTS.

It was discovered that Expat incorrectly handled memory in out-of-memory situations. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS. (CVE-2022-43680)

Original advisory details:

Rhodri James discovered that Expat incorrectly handled memory when processing certain malformed XML files. An attacker could possibly use this issue to cause a crash or execute arbitrary code.

USN-5638-1 fixed a vulnerability in Expat. This update provides the corresponding updates for Ubuntu 16.04 ESM, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 22.10. (CVE-2022-43680) This update also fixes a minor regression introduced in Ubuntu 18.04 LTS.

We apologize for the inconvenience.

Original advisory details:

Rhodri James discovered that Expat incorrectly handled memory when processing certain malformed XML files. An attacker could possibly use this issue to cause a crash or execute arbitrary code.

USN-5638-1 fixed several vulnerabilities in Expat. This update provides the corresponding update for Ubuntu 14.04 ESM.

Original advisory details:

Rhodri James discovered that Expat incorrectly handled memory when processing certain malformed XML files. An attacker could possibly use this issue to cause a crash or execute arbitrary code.