Security feed

25 October 2026

advisoryOfficial CVE List25 Oct 2026

libexpat 2.7.2 through 2.9.0 Denial of Service via XML_ParserReset

libexpat 2.7.2 through 2.9.0 contains a denial of service vulnerability because XML_ParserReset zeroes the direct byte count but never offsets tracked heap allocations. Attackers can submit a large XML document so later documents on the same reset parser fail with XML_ERROR_NO_MEMORY until it is recreated.

libexpat CVE-2026-113351

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-113351

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-113351
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #42342 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 11:42:24 GMT
Publisher date: Tue, 20 Oct 2026 10:41:37 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2026-45186

In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.

libexpat CVE-2026-45186

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-45186

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-45186
Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event: #28358 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:41:08 GMT
Publisher date: Sun, 10 May 2026 06:36:16 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2026-41080

libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.

libexpat CVE-2026-41080

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-41080

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-41080
Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event: #28335 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:40:53 GMT
Publisher date: Thu, 16 Apr 2026 16:52:01 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2026-32778

libexpat before 2.7.5 allows a NULL pointer dereference in the function setContext on retry after an earlier ouf-of-memory condition.

libexpat CVE-2026-32778

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-32778

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-32778
Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event: #28325 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:40:47 GMT
Publisher date: Mon, 16 Mar 2026 07:02:34 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2026-32777

libexpat before 2.7.5 allows an infinite loop while parsing DTD content.

libexpat CVE-2026-32777

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-32777

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-32777
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #28324 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:40:47 GMT
Publisher date: Mon, 16 Mar 2026 06:58:06 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2026-32776

libexpat before 2.7.5 allows a NULL pointer dereference with empty external parameter entity content.

libexpat CVE-2026-32776

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-32776

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-32776
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #28323 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:40:46 GMT
Publisher date: Mon, 16 Mar 2026 06:54:20 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2025-66382

In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time.

libexpat CVE-2025-66382

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2025-66382

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2025-66382
Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event: #27110 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:20:13 GMT
Publisher date: Fri, 28 Nov 2025 00:00:00 GMT

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advisoryOfficial CVE List25 Oct 2026

CVE-2025-59375

libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is submitted for parsing.

libexpat CVE-2025-59375

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2025-59375

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2025-59375
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #27102 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 07:20:07 GMT
Publisher date: Mon, 15 Sep 2025 00:00:00 GMT

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advisoryOfficial CVE List25 Oct 2026

libexpat Heap Buffer Over-read in xmlparse.c via XML_ParseBuffer

libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in xmlparse.c. XML_ParseBuffer advances the parse buffer end with parser->m_bufferEnd += len using a caller-supplied length that is not validated against the allocated buffer size, so repeated XML_ParseBuffer calls move m_bufferEnd past the end of the heap allocation and subsequent parsing reads out of bounds. Reaching this path requires a parse buffer to already be present; otherwise XML_ParseBuffer returns XML_ERROR_NO_BUFFER. A buffer is present after a prior call to XML_GetBuffer, either directly (the common case) or indirectly through a prior XML_Parse call that allocates the buffer internally. The over-read discloses adjacent heap memory to the calling application, recovering heap pointers, libc function pointers, and code pointers sufficient to defeat ASLR and build further exploitation primitives.

libexpat CVE-2026-77214

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-77214

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-77214
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #16546 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 01:18:14 GMT
Publisher date: Wed, 07 Oct 2026 14:35:42 GMT

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24 October 2026

advisoryOfficial CVE List24 Oct 2026

Expat Out-of-Bounds Read via dtdCopy

Expat through 2.8.3 contains an out-of-bounds read vulnerability that allows attackers to trigger memory corruption by processing XML with external entity parsers created via XML_ExternalEntityParserCreate. A struct size mismatch between ELEMENT_TYPE members causes storeAtts to read the attIndex member past allocated memory boundaries, resulting in failure to normalize whitespace in non-CDATA attributes or a wild pointer dereference causing a segfault. This vulnerability was introduced by the fix for CVE-2026-66046.

libexpat CVE-2026-76641

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-76641

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-76641
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #5523 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 22:09:59 GMT
Publisher date: Thu, 20 Aug 2026 17:31:10 GMT

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advisoryOfficial CVE List24 Oct 2026

Expat Denial of Service via storeAtts() Quadratic Complexity

Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.

libexpat CVE-2026-66046

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-66046

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-66046
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #5450 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 22:08:08 GMT
Publisher date: Tue, 18 Aug 2026 14:10:05 GMT

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advisoryOfficial CVE List24 Oct 2026

libexpat 2.7.2 through 2.8.5 Integer Overflow in expat_realloc

libexpat versions 2.7.2 through 2.8.5 contain an integer overflow vulnerability in expat_realloc() function on 32-bit platforms when computing allocation sizes. Attackers supplying malicious XML to applications parsing with vulnerable libexpat can cause heap buffer overflow, memory corruption, or denial of service.

libexpat CVE-2026-102633

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-102633

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-102633
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #3846 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:42:23 GMT
Publisher date: Tue, 29 Sep 2026 16:04:16 GMT

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advisoryOfficial CVE List24 Oct 2026

Expat before 2.8.5 Malformed UTF-16 Acceptance via Unchecked Surrogate

Expat before 2.8.5 fails to validate that a high surrogate in UTF-16 input is followed by a low surrogate, allowing malformed UTF-16 sequences to be accepted. Attackers can supply UTF-16 encoded XML containing lone high surrogates that consume the following code unit, causing Expat to pass unpaired surrogates to applications built with XML_UNICODE and to silently replace input characters in other builds.

libexpat CVE-2026-93990

Structured advisory · Revision 1Original source

Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-93990

libexpat

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Related CVEs: CVE-2026-93990
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event: #3189 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 21:31:10 GMT
Publisher date: Sat, 19 Sep 2026 22:58:11 GMT

Read the original announcement