Read the docs
TI-2026-05223 Aliases CVE-2026-5958GHSA-9r7w-j29g-xqx8

Race Condition in GNU Sed

Priority LOW 10CWE-367Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Partial Red Hat: 1 fixed, 7 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

When sed is invoked with both -i (in-place edit) and --follow-symlinks, the function open_next_file() performs two separate, non-atomic filesystem operations on the same path: 1. resolves symlink to its target and stores the resolved path for determining when output is written, 2. opens the original symlink path (not the resolved one) to read the file. Between these two calls there is a race window. If an attacker atomically replaces the symlink with a different target during that window, sed will: read content from the new (attacker-chosen) symlink target and write the processed result to the path recorded in step 1. This can lead to arbitrary file overwrite with attacker-controlled content in the context of the sed process. This issue was fixed in version 4.10.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00142 3rd percentileScored 2026-11-07
Fix Partial Sed (GNU): 4.10Red Hat: 1 advisoryRed Hat: 1 fixed, 7 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
GNUSed4.1e to before 4.104.10Patch availableCNA
  • Sed VendorGNU Affected 4.1e to before 4.10 Fixed in 4.10 Patch available CNA

Remediation

  • Fix · CNA Sed (GNU) Fixed in 4.10

Red Hat 1 advisory

  • RHSA-2026:10995 Released 2026-04-27 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images sed-4.10-1.hum1@aarch64, sed-4.10-1.hum1@src, sed-4.10-1.hum1@x86_64

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:10995
Not affected: 1 product
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-5958
  2. 2026-10-03 Alias added: GHSA-9r7w-j29g-xqx8
  3. 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