All errata/sisyphus/ALT-PU-2026-19835-2
ALT-PU-2026-19835-2

Package update libxml2 in branch sisyphus

Version2.15.4-alt1
Task#438154
Published2026-10-23
Max severityHIGH
Severity:

Closed issues (20)

BDU:2026-03631
MEDIUM5.9

Уязвимость библиотеки libxml2, связанная с неконтролируемой рекурсией, позволяющая нарушителю вызвать отказ в обслуживании

Published: 2026-03-24Modified: 2026-08-31
CVSS 3.xMEDIUM 5.9
CVSS:3.x/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0MEDIUM 5.4
CVSS:2.0/AV:N/AC:H/Au:N/C:N/I:N/A:C
References
BDU:2026-03632
LOW2.9

Уязвимость библиотеки libxml2, связанная с неконтролируемым расходом ресурсов, позволяющая нарушителю вызвать отказ в обслуживании

Published: 2026-03-24Modified: 2026-08-31
CVSS 3.xLOW 2.9
CVSS:3.x/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0LOW 1.2
CVSS:2.0/AV:L/AC:H/Au:N/C:N/I:N/A:P
References
BDU:2026-03633
LOW3.7

Уязвимость библиотеки libxml2, связанная с неконтролируемой рекурсией, позволяющая нарушителю вызвать отказ в обслуживании

Published: 2026-03-24Modified: 2026-08-31
CVSS 3.xLOW 3.7
CVSS:3.x/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0LOW 2.6
CVSS:2.0/AV:N/AC:H/Au:N/C:N/I:N/A:P
References
CVE-2025-8732
LOW1.9

A vulnerability was found in libxml2 up to 2.14.5. It has been declared as problematic. This vulnerability affects the function xmlParseSGMLCatalog of the component xmlcatalog. The manipulation leads to uncontrolled recursion. Attacking locally is a requirement. The exploit has been disclosed to the public and may be used. The real existence of this vulnerability is still doubted at the moment. The code maintainer explains, that "[t]he issue can only be triggered with untrusted SGML catalogs and it makes absolutely no sense to use untrusted catalogs. I also doubt that anyone is still using SGML catalogs at all."

Published: 2025-08-08Modified: 2026-07-01
CVSS 2.0LOW 1.7
CVSS:2.0/AV:L/AC:L/Au:S/C:N/I:N/A:P
CVSS 3.xLOW 3.3
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS 4.0LOW 1.9
CVSS:4.0/CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
CVE-2026-0989
LOW3.7

A flaw was identified in the RelaxNG parser of libxml2 related to how external schema inclusions are handled. The parser does not enforce a limit on inclusion depth when resolving nested directives. Specially crafted or overly complex schemas can cause excessive recursion during parsing. This may lead to stack exhaustion and application crashes, creating a denial-of-service risk.

Published: 2026-01-15Modified: 2026-09-01
CVSS 3.xLOW 3.7
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
References
CVE-2026-0990
MEDIUM5.9

A flaw was found in libxml2, an XML parsing library. This uncontrolled recursion vulnerability occurs in the xmlCatalogXMLResolveURI function when an XML catalog contains a delegate URI entry that references itself. A remote attacker could exploit this configuration-dependent issue by providing a specially crafted XML catalog, leading to infinite recursion and call stack exhaustion. This ultimately results in a segmentation fault, causing a Denial of Service (DoS) by crashing affected applications.

Published: 2026-01-15Modified: 2026-09-01
CVSS 3.xMEDIUM 5.9
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
CVE-2026-0992
LOW2.9

A flaw was found in the libxml2 library. This uncontrolled resource consumption vulnerability occurs when processing XML catalogs that contain repeated elements pointing to the same downstream catalog. A remote attacker can exploit this by supplying crafted catalogs, causing the parser to redundantly traverse catalog chains. This leads to excessive CPU consumption and degrades application availability, resulting in a denial-of-service condition.

Published: 2026-01-15Modified: 2026-09-01
CVSS 3.xLOW 2.9
CVSS:3.x/CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
References
CVE-2026-11979
LOW1.8

libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper bounds checking. By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv) during input parsing. This results in memory corruption within the stack frame. Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of the xmlcatalog process. This issue has been fixed in the commit c2e233fc. NOTE: The maintainers of this project did not agree that this issue is a vulnerability and considered it a bug.

Published: 2026-06-29Modified: 2026-10-25
CVSS 3.xHIGH 7.8
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 4.0LOW 1.8
CVSS:4.0/CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
CVE-2026-1757
MEDIUM6.2

A flaw was identified in the interactive shell of the xmllint utility, part of the libxml2 project, where memory allocated for user input is not properly released under certain conditions. When a user submits input consisting only of whitespace, the program skips command execution but fails to free the allocated buffer. Repeating this action causes memory to continuously accumulate. Over time, this can exhaust system memory and terminate the xmllint process, creating a denial-of-service condition on the local system.

Published: 2026-02-02Modified: 2026-09-01
CVSS 3.xMEDIUM 6.2
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
CVE-2026-6732
HIGH7.5

A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.

Published: 2026-04-23Modified: 2026-08-31
CVSS 3.xHIGH 7.5
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
CVE-2026-74860
HIGH8.5

A flaw was found in libxml2 with Python bindings enabled. A remote attacker could exploit this vulnerability by providing a specially crafted XML document containing a Document Type Definition (DTD) with enumerated attribute values. This triggers a double-free error in the SAX attributeDecl callback handler, where a string is freed twice. This flaw can lead to a denial of service (DoS) due to a reproducible crash in Python applications using the libxml2 SAX bindings.

Published: 2026-09-08Modified: 2026-10-14
CVSS 3.xHIGH 8.5
CVSS:3.x/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
References
CVE-2026-76781
MEDIUM5.5

A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a `nextCatalog` element lacks its mandatory `catalog` attribute, leading to the application crashing and causing a Denial of Service (DoS).

Published: 2026-09-17Modified: 2026-09-24
CVSS 3.xMEDIUM 5.5
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
References
CVE-2026-86141
LOW3.3

xmlregexp in libxml2 before 2.15.4 has a NULL pointer dereference in xmlRegNewParserCtxt after a strdup failure, i.e., it does not calculate a string length after NULL checking.

Published: 2026-09-05Modified: 2026-09-15
CVSS 3.xLOW 3.3
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
References
CVE-2026-86143
HIGH7.3

In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write callbacks, aka a lack of a check for integer overflow before calling writecallback. This has security relevance for many types of uses of that length value within a callback.

Published: 2026-09-05Modified: 2026-09-15
CVSS 3.xHIGH 7.3
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
References
CVE-2026-86144
HIGH7.8

In xinclude in libxml2 before 2.15.4, xmlXIncludeProcess and xmlXIncludeProcessTree do not propagate parseFlags. This has security relevance for, for example, the XML_PARSE_NONET flag, if (without it) a custom resource loader accesses the internet and triggers XML external entity injection, SSRF, or a denial of service (e.g., for an attacker-controlled internet resource that is intentionally slow).

Published: 2026-09-05Modified: 2026-09-15
CVSS 3.xHIGH 7.8
CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References