CVE-2026-57076
Last modified
CVE-2026-57076 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. YAML::Syck versions before 1.47 for Perl allow a heap use-after-free via an anchor name reused as an anchors-table key in syck_hdlr_add_anchor. In the bundled libsyck an anchor name allocated by syck_strndup is stored both as node->anchor, freed when the node is freed, and as the key in the parser's anchors table. Freeing the node frees the shared key, and a later anchor redefinition makes st_delete compare against the freed key, so st_strcmp reads freed heap memory. EPSS estimates a 0.19% chance of exploitation in the next 30 days.
Description
YAML::Syck versions before 1.47 for Perl allow a heap use-after-free via an anchor name reused as an anchors-table key in syck_hdlr_add_anchor. In the bundled libsyck an anchor name allocated by syck_strndup is stored both as node->anchor, freed when the node is freed, and as the key in the parser's anchors table. Freeing the node frees the shared key, and a later anchor redefinition makes st_delete compare against the freed key, so st_strcmp reads freed heap memory. Anchors are a standard YAML feature and need no special flags, so this is reached on the default Load path. Any caller that runs Load or LoadFile on an untrusted document that redefines an anchor reaches the read of freed memory.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| TODDR | YAML::Syck | < 1.47 |
References
Timeline
- Published
- Last Modified
- Status
- Deferred
Frequently Asked Questions
What is CVE-2026-57076?
How severe is CVE-2026-57076?
How do I fix CVE-2026-57076?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-57054A Use of Incorrectly-Resolved Name or Reference vulnerabilit…6.9
- CVE-2026-57062CMS (Cryptographic Message Syntax) parsing in gpgsm in GnuPG…2.9
- CVE-2026-5707Unsanitized input in an OS command in the virtual desktop se…8.8
- CVE-2026-57073HTML::Bare versions through 0.04 for Perl have an unbounded …9.1
- CVE-2026-57074XML::Bare versions through 0.53 for Perl have an unbounded c…9.1
- CVE-2026-57075YAML::Syck versions before 1.47 for Perl allow an out-of-bou…9.1
- CVE-2026-57077YAML::Syck versions before 1.47 for Perl allow an out-of-bou…7.7
- CVE-2026-57079Net::BitTorrent versions before 2.1.0 for Perl write files o…5.3
- CVE-2026-5708Unsanitized control of user-modifiable attributes in the ses…8.8
- CVE-2026-57080Net::BitTorrent versions through 2.1.0 for Perl allow remote…7.5
- CVE-2026-57081Net::BitTorrent versions through 2.1.0 for Perl allow remote…7.5
- CVE-2026-57082Net::BitTorrent versions before 2.1.0 for Perl generate the …5.9
Are you affected by CVE-2026-57076?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST