CVE-2026-19542
Stack-based out-of-bounds write in tdelete during tree rebalancing
No known exploitation. EPSS puts it in the 12th percentile. No fix published yet.
What to do
No fixed build or workaround is published yet. Limit exposure and watch for a patch.
What it is
From the CVE record
Calling tdelete on a sufficiently deep tree in the GNU C Library version 2.1 to 2.44 may write one pointer past the end of an alloca-allocated array on the stack, which may crash the application. The tdelete implementation keeps an explicit stack of parent nodes for rebalancing, which is grown as needed while descending the tree. Two rebalancing branches push an additional entry without checking the capacity, and write past the array when the stack is exactly full. Triggering this requires a node at a depth of exactly 40 (or 40 plus a multiple of 20), which implies a tree with at least a million nodes, so an attacker must drive a large number of insertions and deletions through an application that uses tsearch and tdelete. The written value is a pointer into a tree node and is not directly attacker controlled. No affected application in common distributions has been identified.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.2% chance of exploitation activity in the next 30 days, which ranks it in the 12th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
6 events over 8 days, from the signal feeds we watch.
- Record updated
- Publishedweakness classified, att&ck mapped, record updated
- OpenVAS check added
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Scored 5.6 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality LowSome restricted information is disclosed, but limited in scope
- Integrity LowData modification is possible but limited in scope or consequence
- Availability LowReduced performance or intermittent disruption of service
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
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