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TI-2026-15896 Aliases CVE-2026-19542GHSA-hhcv-vc8h-vmrg

Stack-based out-of-bounds write in tdelete during tree rebalancing

Priority LOW 25CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Partial Red Hat: 12 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00226 13th percentileScored 2026-11-07
Fix Partial Red Hat: 6 advisoriesRed Hat: 12 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
GNUglibc2.1 – 2.44—No fix listedCNA
  • glibc VendorGNU Affected 2.1 – 2.44 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*——GNU
  • cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:* Versions — — ·GNU

Remediation

Red Hat 6 advisories

  • RHSA-2026:95264 Released 2026-11-04 · Red Hat rating Critical
    Cost Management Metrics Operator Update
    • Cost Management 4 registry.redhat.io/costmanagement/costmanagement-metrics-rhel9-operator
  • RHSA-2026:82939 Released 2026-10-14 · Red Hat rating Important
    Red Hat Update Infrastructure 5.3 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
  • RHSA-2026:80798 Released 2026-10-12 · Red Hat rating Moderate
    glibc security update
    • Red Hat Enterprise Linux AppStream (v. 8) compat-libpthread-nonshared-2.28-251.el8_10.48, glibc-utils-2.28-251.el8_10.48
    • Red Hat Enterprise Linux BaseOS (v. 8) glibc-2.28-251.el8_10.48, glibc-all-langpacks-2.28-251.el8_10.48, glibc-common-2.28-251.el8_10.48 +47
    • Red Hat Enterprise Linux CRB (v. 8) glibc-benchtests-2.28-251.el8_10.48, glibc-nss-devel-2.28-251.el8_10.48, glibc-static-2.28-251.el8_10.48 +1
Show 3 more Red Hat advisories
  • RHSA-2026:79281 Released 2026-10-08 · Red Hat rating Moderate
    glibc security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) glibc-devel-2.34-283.el9_8, glibc-doc-2.34-283.el9_8, glibc-headers-2.34-283.el9_8 +2
    • Red Hat Enterprise Linux BaseOS (v. 9) glibc-2.34-283.el9_8, glibc-all-langpacks-2.34-283.el9_8, glibc-common-2.34-283.el9_8 +47
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) glibc-benchtests-2.34-283.el9_8, glibc-nss-devel-2.34-283.el9_8, glibc-static-2.34-283.el9_8 +2
  • RHSA-2026:76781 Released 2026-10-08 · Red Hat rating Moderate
    glibc security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) glibc-devel-2.39-142.el10_2, glibc-doc-2.39-142.el10_2, glibc-locale-source-2.39-142.el10_2 +1
    • Red Hat Enterprise Linux BaseOS (v. 10) glibc-2.39-142.el10_2, glibc-all-langpacks-2.39-142.el10_2, glibc-common-2.39-142.el10_2 +47
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) glibc-benchtests-2.39-142.el10_2, glibc-nss-devel-2.39-142.el10_2, glibc-static-2.39-142.el10_2 +2
  • RHSA-2026:59721 Released 2026-08-26 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images compat-libpthread-nonshared-2.43-8.2.hum1@aarch64, compat-libpthread-nonshared-2.43-8.2.hum1@x86_64, glibc-2.43-8.2.hum1@aarch64 +47

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Cost Management 4Fixed RHSA-2026:95264
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:76781
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:80798
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:79281
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:76781
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:80798
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:79281
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:80798
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:76781
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:79281
Red Hat Hardened ImagesFixed RHSA-2026:59721
Red Hat Update Infrastructure 5Fixed RHSA-2026:82939
Not affected: 2 products
  • Cost Management 4
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-19542
  2. 2026-10-03 Alias added: GHSA-hhcv-vc8h-vmrg
  3. 2026-10-09 Fix available: RHSA-2026:76781 · Red Hat
  4. 2026-10-09 Fix available: RHSA-2026:79281 · Red Hat
  5. 2026-10-09 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 10) +3 · Red Hat
  6. 2026-10-13 Fix available: RHSA-2026:80798 · Red Hat
  7. 2026-10-13 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · Red Hat
  8. 2026-10-16 Fix available: RHSA-2026:82939 · Red Hat
  9. 2026-10-16 Fix available: Red Hat Update Infrastructure 5 · Red Hat
  10. 2026-10-31 Affected versions changed · Red Hat
  11. 2026-11-06 Fix available: Cost Management 4 · Red Hat
  12. 2026-11-06 Fix available: RHSA-2026:95264 · Red Hat
  13. 2026-11-06 Affected versions changed · Red Hat

References

Advisory 1

Other 1

  • TI-2026-19388 telnetd in GNU Inetutils through 2.7 allows remote authentication bypass via a "-f root"… KEVCVSS 3.1CRITICAL 9.8
  • TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
  • TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
  • TI-2014-05164 GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the… KEVCVSS 3.1HIGH 8.8
  • TI-2023-04522 Glibc: buffer overflow in ld.so leading to privilege escalation KEVCVSS 3.1HIGH 7.8
  • TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
See all 1272 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences